Javascript Popup Function

This is example code for pupup new window using javascript

function show_popup() //
{
var width  = 800;
var height = 500;
var left   = (screen.width  - width)/2;
var top    = (screen.height - height)/2;
var params = 'width='+width+', height='+height+',scrollbars=yes';
params += ', top='+top+', left='+left;
window.open('popup.php','',params);
}