var src

function Source()
{
    if(src == "lblLogin")
    {
        var frame=parent.document.getElementById("main_win")
        frame.setAttribute("src", "Pages/Home.htm")
        src =""
    }
    else if(src == "btnLogin")
    {
        var frame=parent.document.getElementById("main_win")
        frame.setAttribute("src", "Restricted/Confirmation.aspx") 
        src =""       
    }
    else
    {
        var frame=parent.document.getElementById("main_win")
        frame.setAttribute("src", "Pages/Home.htm")
    }   
}