// Javascript from Moodle modules
function getClasses(element) {
	if (document.getElementById(element).getAttribute("class")) return document.getElementById(element).getAttribute("class");
	else return document.getElementById(element).getAttribute("className");
}

function toggleClass(element,c1,c2) {
  var classes = getClasses(element).split(" ");
  
  for (i=0; i<classes.length; i++) {
    if (classes[i] == c1) classes[i] = c2;
    else if (classes[i] == c2) classes[i] = c1;
  }
  
	document.getElementById(element).setAttribute("class", classes.join(" "));
	document.getElementById(element).setAttribute("className", classes.join(" "));
}/**
 * JavaScript for checking or unchecking 
 * all the students or all students in a group.
 *
 * @param toggle Check All/None
 * @param start the first checkbox to be changed
 * @param end the last checkbox to be changed
 * return boolean
 **/
function block_quickmail_toggle(toggle, start, end) {
    // Element ID
    var id = 'mailto'+start;

    // iterate through all of the appropriate checkboxes and change their state
    while(document.getElementById(id) && start != end) {
        document.getElementById(id).checked = toggle;
        start++;
        id = 'mailto'+start;
    }

    return false;
}