function popup(url){
 	helpWindow = window.open(url, 'Information', 'toolbar=no,location=no,status=no,menubar=no,scrollbars=yes,resizable=yes,width=600,height=550,top='+((screen.availHeight/2)-(550/2))+' ,left='+((screen.availWidth/2)-(600/2))+'  '); 
 	helpWindow.focus();
 	return false;
 }
 
 function big_popup(url){
 	helpWindow = window.open(url, 'Information', 'toolbar=no,location=no,status=no,menubar=no,scrollbars=yes,resizable=yes,width=800,height=650,top='+((screen.availHeight/2)-(650/2))+' ,left='+((screen.availWidth/2)-(800/2))+'  '); 
 	helpWindow.focus();
 	return false;
 }