bak

function UI_OpenSizeWindow(pageURL, innerWidth, innerHeight)
{    
    var ScreenWidth = screen.availWidth
    var ScreenHeight = screen.availHeight
    var StartX = (ScreenWidth - innerWidth) / 2
    var StartY = (ScreenHeight - innerHeight) / 2
    window.open(pageURL, '', 'left='+ StartX + ', top='+ StartY + ', Width=' + innerWidth +', height=' + innerHeight + ', resizable=yes, scrollbars=yes, status=yes, toolbar=no, menubar=no, location=no')
}
<a href="#" class="iaaa" onclick="UI_OpenSizeWindow('gff.html', '530','505')">Get Link</a>

// JavaScript Document
function openwin() {
window.open ("mail.html", "newwindow", "height=100, width=400, toolbar=no, menubar=no, scrollbars=no, resizable=no, location=no, status=no")