Object doesn't support property or method 'radopen' in external javascript file

Question

Before I asked, I took a look around first and found a couple solutions but those were based on calling the script server side and I am calling it from the client side. I looked at this.. here and here. So they were no help.

I keep getting an error stating

Object doesn't support property or method 'radopen' in external javascript file

But I have it working in a different project in an external file. I have no idea why its acting like this.

My external code is

function GetModal(url, title, width, height) {
var oWindow = window.radopen(url, title, width, height);
}

Answer 1

I figured out why it was throwing that error. I forgot to add..

<telerik:RadWindowManager ID="RadWindowManager1" runat="server">
        <Windows>
            <telerik:RadWindow ID="RadWindow1" runat="server">

            </telerik:RadWindow>
        </Windows>
    </telerik:RadWindowManager>

to the markup.

No more error.