please anybody help to solve keydown event for enter button problem

[Rocksoft]

Hi,

I am working in asp.net with C# web application, i have used one textbox and image button for search
funtion, i have created one user control for this, but after i have entered value in textbox, i have pressed the
button, its not at all working, if i will use mouse i can able to search values, how to enable to enter key at
keydown event of textbox, the following script i have used ,

function Buttonfocus()
{
 if(event.which || event.keyCode)
 {
  if ((event.which == 13) || (event.keyCode == 13) || (event.which == 10) || (event.keyCode == 10)) 
  {
   document.getElementById("go").click();
   return false;
  }
 }
 else
 {
  return true;
 } 
}

Please anybody to help me solve this problem in my application, advanced thanks for any reply.
Thanks.