Question

I have a page index.jsp available at this link https://www.dropbox.com/s/0smy7nlcmilkqt4/index.jsp.

This file contains a JavaScript method named validateloginForm() and is used to validate input fields.

If the fields are filled then it will redirect to another JSP page, but when I remove the alert("after"); line below the window.open() line, then it does not redirect to another page.

Please let me know why I need to have this alert("after") after calling window.open().

function validateloginForm()
{
    var empId = document.getElementById("empId").value;
    var empPass = document.getElementById("empPass").value;

    if( empId == "" )
    {
        alert("Enter id !");
    }
    else if( empPass == "" )
    {
        alert("Enter password !");
    }
    else
    {                 window.open("validateUser.jsp?"+"empId="+empId+"&empPass="+empPass,"_parent","",""); 
         alert("after");   
     }
}

Answer 1

Because the code after window.open is executed immediately and the window isn’t loaded at that point.

Using .alert is only a coincidence, if you dismissed the alert before the window was loaded, it still wouldn’t work.

var newwin = window.open("validateUser.jsp?"+"empId="+empId+"&empPass="+empPass,"_parent","",""); 
newwin.onload = function() {
    //do stuff
};