function windosa (s,t)
{
var w=500;
var h=500;
var x=(self.screen.width/2)-w/2
var y=(self.screen.height/2)-h/2;
var s1='left='+x+','+'top='+y+',';
var s2='width='+w+','+'height='+h+',';
window.open(s,t, s1+s2+'toolbar=no, menubar=no,status=no, location=no, resizable=no, scrollbars=yes');
}