TypeHere.keyup(function (e) { switch (e.keyCode) { case 188: // ',' var myInputLength = TypeHere.val().length; var myInputText = TypeHere.val().substring(0, myInputLength - 1); // remove ',' TypeHere.width(myInputLength * 6 + 15); //Check for email validation. //You can apply webservices for any type of validation. var emailReg = /^([\w-\.]+@([\w-]+\.)+[\w-]{2,4})?$/; if (myInputText.length == 0) { TypeHere.val(''); return false; } if(!emailReg.test(myInputText)) { alert('Email Is Invalid'); TypeHere.val(''); return false; } //Create the list item on fly and apply the css CreateLi(myInputText) //Save into Textbox or HiddenField var strValue = txtValues.val() + myInputText + ';'; txtValues.val(strValue); //Push the textbox to the right TypeHere.width(myInputLength * 6 + 15); //Make the input width to default and set as blank liTypeHere.css('left', TypeHere.position().left + TypeHere.width() + 10); TypeHere.val(''); TypeHere.width(10); break; } });