This method is used in the processing page to trigger a client-side function from the server,
before the processing starts.

After the client-side function is executed, the server-side processing continues.

You can have unlimited number of ExecBeforeLoad methods, and as a parameter
you can have a javascript code or the name of a javascript function.

Here is a short example:

    public string onClick(int myInt)
    {
        // ExecBeforeLoad examples
        ExecBeforeLoad("alert('some text')");
        ExecBeforeLoad("someCustomFunction()");

        // return the number received as argument multiplied by 10
        return myInt * 10;
    }
		

See also ExecBeforeLoad example.