Question

I have a function that set selected = true. I have a dropdown list of countries. Each option has ids such as USA, GER…

    function nation(arg) 
{
    if (arg == '<?php echo $this->escape($this->user->get( 'country' ));?>')
        document.getElementById(arg).selected = true;
}

window.onload = nation('<?php echo $this->escape($this->user->get( 'country' ));?>');

I’am sure that php code returns me the correct country, but javascript debugger says:

SCRIPT5007: Unable to set value of the property 'selected': object is null or undefined 

What is the problem here?

Answer 1

You are calling nation immediately and then assigning its return value to onload, so you are almost certainly calling it before the <select> has been added to the DOM.

You need to assign a function.

window.onload = function () {
    nation('<?php echo $this->escape($this->user->get( 'country' ));?>');
};