Question

I’m writing a javascript snippet that will validate the signup form fields.
for some reason, the onsubmit function, is also called when the page loads.

window.onload = function validate_signup_form() {

var form_element = document.getElementById("signup_form");
var onload_values = document.forms["signup_form"];
var test = onload_values.elements[0].value;
var required_fields = new Array();

document.getElementById("signup_form").onsubmit = check_values();

function check_values() 
{
    var current_values = document.forms["signup_form"];
    for (x in current_values) 
    {
        if (current_values[x].value == onload_values[x].value) 
        {
            // Error: The form values match the initial ones
            return false;
        } 
        elseif (current_values[x].value.toLowerCase() == onload_values[x].value.toLowerCase()) 
        {
            // Error: The form values match the initial ones
            return false;           
        }
        elseif (current_values[x].value.toUpperCase() == onload_values[x].value.toUpperCase()) 
        {
            // Error: The form values match the initial ones
            return false;           
        }
    }
};
};

Shouldn’t check_values(); run only on submit ?

Answer 1

You are setting the onsubmit property to the value returned by check_values(); Change to the following:

document.getElementById("signup_form").onsubmit = check_values;