The following is my HTML:
Try the following:
In HTML add an onclick event handler for Make a new account
button:
In JavaScript:
function register() {
this.action = 'register.php';
return true;
}
If this does not work, you may try:
function register() {
var frm = document.getElementById("myform");
frm.action = 'register.php';
return true;
}
One or both of the above mentioned solution should work for you. Prefer the first approach as it is cleaner.
Please take this as a starting point not a copy-paste solution and follow the best practices for development.