// checks username and password in loginpage: login.php
function checkLogin(myForm) 
{
	if(myForm.elements['username'].value=="") {
		alert("Please enter your user name.");
		myForm.elements['username'].focus();
	} else if(myForm.elements['password'].value=="") {
		alert("Please enter your password.");
		myForm.elements['password'].focus();
	} else {
		myForm.submit();
	}
}

// checks radio buttons in subcategory generation: lib_html/test_subcats ()
function checkTestValues (myForm) {
	var oneIsChecked = false;
	
	for(var i=0; i< myForm.testvalues.length; i++) {
		if (myForm.testvalues[i].checked) {
			oneIsChecked = true;
		}
	}
	
	if (!oneIsChecked) {
		alert('You need to choose a test');
	} else {
		myForm.submit();
	}
}