// JavaScript Document
function chImage(element, newSrc){
	element.src =  newSrc;
}
function chRefImage(id, newSrc){
	chImage(document.getElementById('id'), newSrc);
}
function preloader(preloadArray){
	if(!preloadArray){
		return;
	}
	for(var i=0;i<preloadArray.length; i++){
		var pic = new Image(100,100); 
		pic.src=preloadArray[i];
	}
}
function toggleDiv(divID){
	var element = document.getElementById(divID);
	if(element.className != 'hide'){
		element.className = 'hide'; 
	}else{
		element.className = 'show'; 
	}
}

function showHide(n, prefix, sel){
	for(i=0;i<n; i++){
		var currId = prefix + i;
		var element = document.getElementById(currId);
		if(currId == sel){
			element.className = 'show'; 
		}else{
			element.className = 'hide'; 
		}
	}
}
function showAll(n, prefix){
	for(i=0;i<n; i++){
		var currId = prefix + i;
		var element = document.getElementById(currId);
		element.className = 'show'; 
	}
}
function hideAll(n, prefix){
	for(i=0;i<n; i++){
		var currId = prefix + i;
		var element = document.getElementById(currId);
		element.className = 'hide'; 
	}
}
function randomShow(n, prefix){
	maxN=n-1;
	var rNum = Math.round(Math.random()*maxN);
	var sel = prefix + rNum;
	showHide(n, prefix, sel);
}
function firstShow(n, prefix){
	var sel = prefix + "0";
	//document.write(sel);
	showHide(n, prefix, sel);
}
/*obsfucate addresses */
function mailWrite(uName, dom){
	var cry=String.fromCharCode(109,97,105,108,116,111,58);
	if(dom == undefined){
		var dom = "abdn.ac.uk";
	}
	var addy=uName;
	addy += String.fromCharCode(64);
	addy +=dom;
	
	document.write("<br />Contact by email: <a href=\"" + cry + addy + "\">" + addy + "</a>");

}
function courseDetailsWrite(tutor, dept, credits, semester, compulsory){
	var listing = "<ul><li>Tutor: " + tutor + " (<em>" + dept + "</em>)</li>";
	listing += "<li>Credits: " + credits + "</li>";
	if(semester != ""){
		listing += "<li>Semester: " + semester + "</li>";
	}
	if(compulsory == true){
		listing += "<li class='bold'>Compulsory Course</li>";
	}
	listing += "</ul>";
	document.write(listing);
}

function showSwitchWrite(n, prefix){
	var innerVar = "'" + n +"', '" + prefix + "'";
	var switchString = "<p class='small' id='toggleSwitch'><a href=\"javascript:showAll(" + innerVar + ")\">show all</a> | <a href=\"javascript:hideAll(" + innerVar + ")\">hide all</a></p>";
	document.write(switchString);
}