// Common generic AJAX function
	function ajaxc(url, vars, pos) {

		var request =  new XMLHttpRequest();
		request.open("POST", url, true);
		request.setRequestHeader("Content-Type",
				                     "application/x-www-form-urlencoded");
	 
		request.onreadystatechange = function() {
			var done = 4, ok = 200;
			if (request.readyState == done && request.status == ok) {
				if (request.responseText && pos != "") {
				  document.getElementById(pos).innerHTML = request.responseText;
				}
			}
		};
		request.send(vars);
	}
	
	// Encodes values for URLs
	function urlencode(string) {
		string = encodeURIComponent(string);
		return string.replace(/~/g,'%7E').replace(/%20/g,'+');
	}

	// Open centered popup window
	function OpenCentered(psUrl, psName, piWidth, piHeight, psFlags) {
		var iX=(screen.width-piWidth-20)/2;
		var iY=(screen.height-piHeight-30)/2;
		open(psUrl, psName, 'width=' + piWidth + ',height=' + piHeight + ',scrollbars=1,left=' + iX + ',top=' + iY +  ',screenX=' + iX + ',screenY=' + iY + psFlags);
	}
	
	function IDEA_students() {
		var job_market = document.getElementById("job_market").checked;
		var grade = document.getElementById("grade").value;
		var master = document.getElementById("master").checked;
		document.getElementById("grade_job_market_extra").style.display = "none";
		document.getElementById("job_market_extra").style.display = "none";
		document.getElementById("grade_extra").style.display = "none";
		if(master == true || grade == 8 || job_market == true) document.getElementById("grade_job_market_extra").style.display = "block";
		if(master == true || grade == 8 || job_market == true) document.getElementById("job_market_extra").style.display = "block";
		if(master == true || grade == 8) document.getElementById("grade_extra").style.display = "block";
	}
	
	function IDEA_subject_delete() {
		var agree=confirm("Permanently delete this subject?");
		if(agree) {
			return true;
		} else {
			return false;
		}
	} 
	
	function IDEA_academic_calendar(time) {
		ajaxc("http://idea.uab.es/_srv/altMind/ajax/IDEA_academic_calendar.php", "time=" + time, "the_calendar");
	}
	
	function IDEA_pdfs(task, limit) {
		var selected = '';
		var i=1;
		for(i=1; i<=limit; i++) {
			if(task == 0) {
				document.getElementById("IDEA_pdf_" + i).checked = true;
			}
			if(task == 1) {
				if(document.getElementById("IDEA_pdf_" + i).checked == true) {
					document.getElementById("IDEA_pdf_" + i).checked = false;
				} else {
					document.getElementById("IDEA_pdf_" + i).checked = true;
				}
			}
			if(task == 2) {
				document.getElementById("IDEA_pdf_" + i).checked = false;
			}
			if(task == 3) {
				if(document.getElementById("IDEA_pdf_" + i).checked == true) {
					selected += "." + document.getElementById("IDEA_pdf_" + i).value;
				}
			}
		}
		if(task == 3) {
			window.open("http://idea.uab.es/_srv/altMind/pdfs_data.php?inc=" + selected, "_self");
		}
	}
	
	function IDEA_subject_file_show(id) {
		ajaxc("http://idea.uab.es/_srv/faculty_upload.php", "id_subject=" + id, "uploaded");
	}
	
	function IDEA_subject_file_delete(id, file_id) {
		var agree=confirm("Delete this file?");
		if(agree) {
			ajaxc("http://idea.uab.es/_srv/faculty_upload.php", "id_subject=" + id + "&delete_file=" + file_id, "uploaded");
		} else {
			return false;
		}
	}