function isSpaceKey(evt) {
         //   debugger;
           var charCode = (evt.which) ? evt.which : event.keyCode
           
           if ((charCode < 47 || charCode > 57) &&  charCode != 8) {
               alert("Enter Numeral Values only!");
               return false;
           }
           return true;
       }

I have created a .aspx page in it i have added gew javascript function containing alert(). But niether the functions nor the alerts are invoking.why? i have created a javascript function on keypress event as: function isSpaceKey(evt) { // debugger; var charCode = (evt.which) ? evt.which : event.keyCode if ((charCode < 47 || charCode > 57) && charCode != 8) { alert("Enter Numeral Values only!"); return false; } return true; } and added validation summary in .aspx page enabling its message box if user validation fails . But it is also not working. Before using Firefox i was using IE on which it was working fine. What is the problem? Thanks.