jQuery keyup() illegal characters

Question

I have a field and want to prevent some illegal characters while showing the user as he types. How can I do this in follow example?

  $(\'input\').bind(\"change          


        

Answer 1

You may use the indexOf to determine if a string contains a certain char...

vowels = array('"', "<", ">", "&");

$('input').bind("change keyup", function()
{
   var val = $(this).attr("value");
   var illegal = '';       
   $(vowels).each(function()
   {
      if(val.indexOf(this)!=-1)
      {
          illegal= this;
          break;
      }
   });
   if(illegal != '') 
   {
       $(this).css("background", "red");
       val = val.replace(illegal, "");
       $(this).attr("value", val)
   }
});