Problems with opening the link on another page - asp.net

Question

I am working on contact page where the client can enter the postcode which will take them to google maps for directions to the company, the problem which i am having is although the hyperlink is set to target_blank but still the window opens on the back hand instead of opening in front of the website page. I have no idea why it opens on the back hand and focus is on the current page instead of moving it to google map page
<a href="#" target="_blank">
<img alt="" src="/images/contactUs/directionbtn.png" onclick="return openDirections(1);" /></a>
<script type="text/javascript">
function openDirections(NumVal) {
if (NumVal == 1) {
if (document.getElementById("<%=txtPostcode.ClientID%>").value == "") {
alert("PostCode can not be blank");
document.getElementById("<%=txtPostcode.ClientID%>").focus();
return false;
}
else {
var regPostcode = /^([a-zA-Z]){1}([0-9][0-9]|[0-9]|[a-zA-Z][0-9][a-zA-Z]|[a-zA-Z][0-9][0-9]|[a-zA-Z][0-9]){1}([ ])([0-9][a-zA-z][a-zA-z]){1}$/;
var tempURL = document.getElementById("<%=txtPostcode.ClientID%>").value;
if (regPostcode.test(tempURL) == false) {
alert("Please Enter a Valid PostCode");
document.getElementById("<%=txtPostcode.ClientID%>").focus();
return false;
}
else {
var url = 'http://maps.google.co.uk/maps?saddr={' + $('#<%=txtPostcode.ClientID%>').val() + '}&daddr=&daddr=646+Preston+Rd,+Clayton-le-Woods,+Chorley+PR6+7EH,+United+Kingdom&iwloc=1&dq=Tangent+Design';
document.location = url;
return true;
}
}
}
</script>

Answer 1

Try window.open(url); instead of of document.location = url;

Answer 2

All I see you doing is setting the url of the current window. Maybe try using something like this to open a new window instead.
window.open('url to open',)
in place of document.location = url

Answer 3

Each browser can be configured to handle how new pages are opened. Take a look at the preferences in the browser you are using, and see if that is the behavior that you currently have configured.

Answer 4

I think this is what you are looking for:
var x = window.open(URL, 'name', '...');
x.focus();