Java script Open new window

[iamchamith]

I open new window using javascript as like this, in the Main page using several links & that link pass the id to the javascript function call moreWindoe()
eg->

<a onclick="morewindw(1)">link 1</a>
<a onclick="morewindw(2)">link 2</a>
<a onclick="morewindw(3)">link 3</a>

function moreWindow(id){
    window.open('moredata.aspx?val='+id+'','mywindow','width=650,height=540','location=no');
    return false;
}

when i am click the Main page's link , the new window will open called moredata.aspx...

my question is when i click mainPage link at the first ,
moredata window comes first layer of the screen...

if i click some place of themainPage , provios moreData window is goes to second layer of screen
after now i click another link for open new window,that window always open second layer of the screen...I must want to get this new window called moreData to first layer

How i do this
thanks