jQuery.fn.maxLength = function(max){
       this.each(function(){
           //Get the type of the matched element
          var type = this.tagName.toLowerCase();
          //If the type property exists, save it in lower case
            var inputType = this.type? this.type.toLowerCase() : null;
           //Check if is a input type=text OR type=password
           if(type == "input" && inputType == "text" || inputType == "password"){
              //Apply the standard maxLength
              this.maxLength = max;
         }
       //Check if the element is a textarea
          else if(type == "textarea"){
             //Add the key press event
             this.onkeypress = function(e){
                 //Get the event object (for IE)
                  var ob = e || event;
                  //Get the code of key pressed
                  var keyCode = ob.keyCode;
                 //Check if it has a selected text
                   var hasSelection = document.selection? document.selection.createRange().text.length > 0 : this.selectionStart != this.selectionEnd;
                //return false if can't write more
                  return !(this.value.length >= max && (keyCode > 50 || keyCode == 32 || keyCode == 0 || keyCode == 13) && !ob.ctrlKey && !ob.altKey && !hasSelection);
              };
               //Add the key up event
              this.onkeyup = function(){
                  //If the keypress fail and allow write more text that required, this event will remove it
                   if(this.value.length > max){
                     this.value = this.value.substring(0,max);
                   }
               };
          }
      });
 };