Center Popup Window

by Lal Prakash

HTML

<a onclick="javascript:window.open('https://www.thelink.org/faf/login/loginParticipantPopUp.asp?ievent=1138380','loginwin','menubar=no,scrollbars=yes,resizable=yes,width=400,height=200')" href="#">click here</a>

<input type="button" value="Change URL" onclick="setClick();">

JavaScript

function changeURL() {
    var left = (screen.width / 2) - (400 / 2);
    var top = (screen.height / 2) - (200 / 2);
    var url = "javascript:window.open('https://www.thelink.org/faf/login/loginParticipantPopUp.asp?ievent=1138380','loginwin','menubar=no,scrollbars=yes,resizable=yes,width=400,height=200, top=" + top + ", left=" + left + "')";
    return url;
}

function setClick() {
    document.getElementsByTagName("a")[0].setAttribute("onClick", changeURL());
}