diff --git a/jquery.tagsinput.js b/jquery.tagsinput.js
index f57d6e9..fb71d79 100644
--- a/jquery.tagsinput.js
+++ b/jquery.tagsinput.js
@@ -18,12 +18,60 @@
 
 	var delimiter = new Array();
 	var tags_callbacks = new Array();
-	$.fn.doAutosize = function(options){
-    alert(JSON.stringify(options));
-  }
+	$.fn.doAutosize = function(o){
+    var minWidth = $(this).data('minwidth'),
+        maxWidth = $(this).data('maxwidth'),
+        val = '',
+        input = $(this),
+        testSubject = $('#'+$(this).data('tester_id'));
+
+    if (val === (val = input.val())) {return;}
+
+    // Enter new content into testSubject
+    var escaped = val.replace(/&/g, '&amp;').replace(/\s/g,' ').replace(/</g, '&lt;').replace(/>/g, '&gt;');
+    testSubject.html(escaped);
+    // Calculate new width + whether to change
+    var testerWidth = testSubject.width(),
+        newWidth = (testerWidth + o.comfortZone) >= minWidth ? testerWidth + o.comfortZone : minWidth,
+        currentWidth = input.width(),
+        isValidWidthChange = (newWidth < currentWidth && newWidth >= minWidth)
+                             || (newWidth > minWidth && newWidth < maxWidth);
+
+    // Animate width
+    if (isValidWidthChange) {
+        input.width(newWidth);
+    }
+
+
+  };
   $.fn.resetAutosize = function(options){
-    alert(JSON.stringify(options));
-  }
+    // alert(JSON.stringify(options));
+    var minWidth =  $(this).data('minwidth') || options.minInputWidth || $(this).width(),
+        maxWidth = $(this).data('maxwidth') || options.maxInputWidth || ($(this).closest('.tagsinput').width() - options.inputPadding),
+        val = '',
+        input = $(this),
+        testSubject = $('<tester/>').css({
+            position: 'absolute',
+            top: -9999,
+            left: -9999,
+            width: 'auto',
+            fontSize: input.css('fontSize'),
+            fontFamily: input.css('fontFamily'),
+            fontWeight: input.css('fontWeight'),
+            letterSpacing: input.css('letterSpacing'),
+            whiteSpace: 'nowrap'
+        }),
+        testerId = $(this).attr('id')+'_autosize_tester';
+    if(! $('#'+testerId).length > 0){
+      testSubject.attr('id', testerId);
+      testSubject.appendTo('body');
+    }
+
+    input.data('minwidth', minWidth);
+    input.data('maxwidth', maxWidth);
+    input.data('tester_id', testerId);
+    input.css('width', minWidth);
+  };
 	$.fn.addTag = function(value,options) {
 			var options = jQuery.extend({focus:false,callback:true},options);
 			this.each(function() { 
@@ -135,7 +183,9 @@
       'unique':true,
       removeWithBackspace:true,
       placeholderColor:'#666666',
-      autosize: true
+      autosize: true,
+      comfortZone: 20,
+      inputPadding: 6*2,
     },options);
 
 		this.each(function() { 
@@ -181,7 +231,8 @@
 			}		
 			if (settings.interactive) { 
 				$(data.fake_input).val($(data.fake_input).attr('data-default'));
-				$(data.fake_input).css('color',settings.placeholderColor);		
+				$(data.fake_input).css('color',settings.placeholderColor);
+        $(data.fake_input).resetAutosize(settings);
 		
 				$(data.holder).bind('click',data,function(event) {
 					$(event.data.fake_input).focus();