How do I make the search engine result not to activate the popup blocker?

Question

From first glance this seems perfectly fine. But it has a bug I want to fix.

How do I make the search engine result not to activate the popup blocker? The function works perfectly except that each time somebody clicks the search button to open the result in a separate tab window, they need to tell the popup blocker of the browser that it is okay.

If the page with the codes is not in a iframe it works as it should, but when it is in a iframe it activates the popup blocker on the browser. So how do I make it not to activate the popup blocker alert or to ignore the popup blocker allert in the browser regardless in what browser it is used?

JavaScript:

<script language="JavaScript">
function handleKeyPress(e)
{
    var key=e.keyCode || e.which;
    if (key==13){
    event.preventDefault();
    GoToURL();
    }
     return false;
}

function GoToURL()
{
    var URLis;
    Advance = document.URLframe.Adv.value
    URLis = document.URLframe.u.value
    BegEnd = document.URLframe.begnd.value
    Word1 = document.URLframe.wo1.value
    Code = document.URLframe.co.value
    Word2 = document.URLframe.wo2.value
    Lang = document.URLframe.lr.value
    Country = document.URLframe.cr.value
    {
        var location= ("https://duckduckgo.com/?q=" + Advance + URLis + BegEnd + Word1 + Code + Word2 + BegEnd + Lang + Country + "&ia=definition");
        window.open(location, '_blank');
    }
}
</script>

HTML:

<input type="text" name="u" size="71" value="" placeholder=" Type your Search Text here and click &raquo;&raquo; Search &laquo;&laquo; ... " id="SeekBox" onkeypress="handleKeyPress(event)">
<input type="button" id="SeekButton" onclick="GoToURL(this)" onkeypress="handle(event)" value=" &raquo;&raquo; Search &laquo;&laquo; ">