function fnOnKeyPress() 
       { 
           var obj = window.event.srcElement; 
           if  (obj.value.length >= obj.maxLength) 
               event.returnValue = false;           
       }       
       function fnOnPaste() 
       { 
           var obj = window.event.srcElement; 
           var maxLen = obj.maxLength; 
           var curLen = obj.value.length; 
           if (curLen >= maxLen) 
           { 
               event.returnValue = false; 
               return; 
           } 
           var newText = window.clipboardData.getData("text"); 
           if (newText.length + curLen <=maxLen ) 
           { 
               event.returnValue = true; 
               return; 
           } 
           event.returnValue = false; 
           if (obj.enableTruncate ) 
           { 
               obj.value = obj.value + newText.substring(0,maxLen-curLen); 
           } 
       }      
       function fnSetMaxLength(objName, maxLen, enableTruncate) 
       { 
           var obj = document.all(objName); 
           obj.maxLength = maxLen; 
           obj.enableTruncate = enableTruncate; 
           obj.onkeypress = fnOnKeyPress; 
           obj.onpaste = fnOnPaste; 
       }