diff --git a/auto-complete.css b/auto-complete.css
index 4261b1d..634abaa 100644
--- a/auto-complete.css
+++ b/auto-complete.css
@@ -4,6 +4,6 @@
     /* core styles should not be changed */
     position: absolute; display: none; z-index: 9999; max-height: 254px; overflow: hidden; overflow-y: auto; box-sizing: border-box;
 }
-.autocomplete-suggestion { position: relative; padding: 0 .6em; line-height: 23px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; font-size: 1.02em; color: #333; }
+.autocomplete-suggestion, .noresults-suggestion { position: relative; padding: 0 .6em; line-height: 23px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; font-size: 1.02em; color: #333; }
 .autocomplete-suggestion b { font-weight: normal; color: #1f8dd6; }
 .autocomplete-suggestion.selected { background: #f0f0f0; }
diff --git a/auto-complete.js b/auto-complete.js
index 2f5a88c..b3d84aa 100644
--- a/auto-complete.js
+++ b/auto-complete.js
@@ -43,7 +43,12 @@ var autoComplete = (function(){
                 var re = new RegExp("(" + search.split(' ').join('|') + ")", "gi");
                 return '<div class="autocomplete-suggestion" data-val="' + item + '">' + item.replace(re, "<b>$1</b>") + '</div>';
             },
-            onSelect: function(e, term, item){}
+            onSelect: function(e, term, item){},
+            renderNoResults: function() { return '<div class="noresults-suggestion">No results returned</div>'; },
+            preventSource: function(val){ return false;},
+            sourcePrevented: function(val) {},
+            widthScale: 1,
+            valueFilter: function(val, lastVal) { return val; }
         };
         for (var k in options) { if (options.hasOwnProperty(k)) o[k] = options[k]; }
 
@@ -65,7 +70,7 @@ var autoComplete = (function(){
                 var rect = that.getBoundingClientRect();
                 that.sc.style.left = Math.round(rect.left + (window.pageXOffset || document.documentElement.scrollLeft) + o.offsetLeft) + 'px';
                 that.sc.style.top = Math.round(rect.bottom + (window.pageYOffset || document.documentElement.scrollTop) + o.offsetTop) + 'px';
-                that.sc.style.width = Math.round(rect.right - rect.left) + 'px'; // outerWidth
+                that.sc.style.width = (o.widthScale * Math.round(rect.right - rect.left)) + 'px'; // outerWidth
                 if (!resize) {
                     that.sc.style.display = 'block';
                     if (!that.sc.maxHeight) { that.sc.maxHeight = parseInt((window.getComputedStyle ? getComputedStyle(that.sc, null) : that.sc.currentStyle).maxHeight); }
@@ -84,7 +89,7 @@ var autoComplete = (function(){
             addEvent(window, 'resize', that.updateSC);
             document.body.appendChild(that.sc);
 
-            live('autocomplete-suggestion', 'mouseleave', function(e){
+            live('autocomplete-suggestion', 'mouseout', function(e){
                 var sel = that.sc.querySelector('.autocomplete-suggestion.selected');
                 if (sel) setTimeout(function(){ sel.className = sel.className.replace('selected', ''); }, 20);
             }, that.sc);
@@ -97,7 +102,7 @@ var autoComplete = (function(){
 
             live('autocomplete-suggestion', 'mousedown', function(e){
                 if (hasClass(this, 'autocomplete-suggestion')) { // else outside click
-                    var v = this.getAttribute('data-val');
+                    var v = o.valueFilter(this.getAttribute('data-val'), that.value);
                     that.value = v;
                     o.onSelect(e, v, this);
                     that.sc.style.display = 'none';
@@ -123,8 +128,7 @@ var autoComplete = (function(){
                     that.sc.innerHTML = s;
                     that.updateSC(0);
                 }
-                else
-                    that.sc.style.display = 'none';
+                else that.sc.innerHTML = o.renderNoResults();
             }
 
             that.keydownHandler = function(e){
@@ -135,15 +139,15 @@ var autoComplete = (function(){
                     if (!sel) {
                         next = (key == 40) ? that.sc.querySelector('.autocomplete-suggestion') : that.sc.childNodes[that.sc.childNodes.length - 1]; // first : last
                         next.className += ' selected';
-                        that.value = next.getAttribute('data-val');
+                        that.value = o.valueFilter(next.getAttribute('data-val'), that.value);
                     } else {
                         next = (key == 40) ? sel.nextSibling : sel.previousSibling;
                         if (next) {
                             sel.className = sel.className.replace('selected', '');
                             next.className += ' selected';
-                            that.value = next.getAttribute('data-val');
+                            that.value = o.valueFilter(next.getAttribute('data-val'), that.value);
                         }
-                        else { sel.className = sel.className.replace('selected', ''); that.value = that.last_val; next = 0; }
+                        else { sel.className = sel.className.replace('selected', ''); that.value = o.valueFilter(that.last_val, that.val); next = 0; }
                     }
                     that.updateSC(0, next);
                     return false;
@@ -168,13 +172,19 @@ var autoComplete = (function(){
                             clearTimeout(that.timer);
                             if (o.cache) {
                                 if (val in that.cache) { suggest(that.cache[val]); return; }
-                                // no requests if previous suggestions were empty
-                                for (var i=1; i<val.length-o.minChars; i++) {
-                                    var part = val.slice(0, val.length-i);
-                                    if (part in that.cache && !that.cache[part].length) { suggest([]); return; }
-                                }
+                                //other truthy numeric values of course invoke "strict" cache usage 
+                                else if (o.cache == 1) {
+                                    // no requests if previous suggestions were empty
+                                    for (var i=1; i<val.length-o.minChars; i++) {
+                                        var part = val.slice(0, val.length-i);
+                                        if (part in that.cache && !that.cache[part].length) { suggest([]); return; }
+                                    }
+                                }                                
                             }
-                            that.timer = setTimeout(function(){ o.source(val, suggest) }, o.delay);
+                            if (!o.preventSource(val)){
+                                that.timer = setTimeout(function(){ o.source(val, suggest) }, o.delay);
+                            } 
+                            else o.sourcePrevented(val);
                         }
                     } else {
                         that.last_val = val;
diff --git a/demo.html b/demo.html
index ab7b1a2..e33b0eb 100644
--- a/demo.html
+++ b/demo.html
@@ -110,7 +110,7 @@ <h3>Settings</h3>
             <tr><td>delay</td><td>150</td><td>The delay in milliseconds between when a keystroke occurs and when a search is performed. A zero-delay is more responsive, but can produce a lot of load.</td></tr>
             <tr><td>offsetLeft</td><td><i>0</i></td><td>Optional left offset of the suggestions container.</td></tr>
             <tr><td>offsetTop</td><td><i>1</i></td><td>Optional top offset of the suggestions container.</td></tr>
-            <tr><td>cache</td><td><i>true</i></td><td>Determines if performed searches should be cached.</td></tr>
+            <tr><td>cache</td><td><i>1</i></td><td>Determines if performed searches should be cached. Falsy values turn caching off, 1 turns on (legacy) non-strict cache-checking, any other numeric values turn on strict cache-checking.</td></tr>
             <tr>
                 <td>menuClass</td><td><i>''</i></td>
                 <td>Custom class/es that get/s added to the dropdown menu container.
@@ -127,6 +127,19 @@ <h3>Settings</h3>
 }</code></pre>
                 </td>
             </tr>
+            <tr>
+                <td>renderNoResult</td><td><i>function</i></td>
+                <td>
+                    <p>A function that gives you control over what is displayed when there are no results to suggest. Default:</p>
+<pre class="prettyprint" style="white-space:pre-wrap"><code>renderNoResults: function(){
+    return '&lt;div class=&quot;noresults-suggestion&quot;&gt;No results returned&lt;/div&gt;';
+}</code></pre>
+                </td>
+            </tr>
+            <tr>
+                <td>widthScale</td><td><i>1</i></td>
+                <td><p>Optional coefficient applied to base suggestion width.</p></td>
+            </tr>
 
             <tr><td colspan="3">&nbsp;</td></tr>
             <tr><th>Callbacks</th><th colspan="2"></th></tr>
@@ -136,6 +149,21 @@ <h3>Settings</h3>
                 <span class="inline-code">term</span> is the selected value.
                 and <span class="inline-code">item</span> is the item rendered by the renderItem function.
             </td></tr>
+            <tr><td>preventSource(val)</td><td colspan="2">
+                A callback function that fires before the source function would normally be called to evaluate conditions, and should return a truthy value.
+                <span class="inline-code">val</span> is the currently entered value.
+            </td></tr>
+            <tr><td>sourcePrevented(val)</td><td colspan="2">
+                A callback function that fires when the preventSource function returns true and the source function is prevented.
+                <span class="inline-code">val</span> is the value previously passed to preventSource.
+            </td></tr>
+            <tr>
+                <td>valueFilter(val, lastVal)</td><td colspan="2">
+                A callback function that fires prior to onSelect, allowing exact specification of how the new value should be handled, to provide to onSelect.
+                <span class="inline-code">val</span> is the new value from the last selection.
+                <span class="inline-code">lastVal<span> is the value currently stored.
+                valueFilter should return the appropriate value to be stored.
+            </tr>
 
             <tr><td colspan="3">&nbsp;</td></tr>
             <tr><th>Public Methods</th><th colspan="2"></th></tr>
@@ -276,6 +304,12 @@ <h4>Advanced suggestions handling and custom layout</h4>
                 for (i=0;i<choices.length;i++)
                     if (~choices[i].toLowerCase().indexOf(term)) suggestions.push(choices[i]);
                 suggest(suggestions);
+            },
+            preventSource: function(val) {
+                return "python".substring(0, val.length) === val.toLowerCase();
+            },
+            sourcePrevented: function(val) {
+                if (val.toLowerCase() === 'python') alert('I don\'t make suggestions for snakes! (Maybe their AJAX requests take too long to return?)');
             }
         });
 
diff --git a/readme.md b/readme.md
index 0a155c3..11e23e4 100644
--- a/readme.md
+++ b/readme.md
@@ -22,6 +22,22 @@ https://goodies.pixabay.com/javascript/auto-complete/demo.html
 
 ## Changelog
 
+### Version 1.0.7 - 2017/03/15
+
+* Modified de-select handler to fire on mouseout, rather than mouseleave. Fixed improper valueFunction references.
+
+### Version 1.0.7 - 2017/03/10
+
+* Added valueFilter callback and documentation.
+
+### Version 1.0.6 - 2017/03/10
+
+* Made cache: 1 implement old non-strict key cache searching, all other truthy values implement only strict caching.
+
+### Version 1.0.5 - 2017/03/10
+
+* Added renderNoResults, preventSource, sourcePrevented, and widthScale options
+
 ### Version 1.0.4 - 2016/02/10
 
 * Included pull #6 and added offsetLeft/offsetTop as optional parameter for suggestions container.