function visaPopup(page, w, h) 
{

w = 1 * w;
h = 1 * h;


x = window.screen.availWidth;
y = window.screen.availHeight;


w = w - 13;
h = h - 30;

x = 1 * x;
y = 1 * y;

y = 0.2 * y;
x = (x - w)/2;

windowInstance = window.open(page, "",config='width='+w+',height='+h+',scrollbars=0,resizable=0,top='+y+',left='+x)
}