var http_request = false;

function makeRequest(url, parameters) {
	http_request = false;
	if (window.XMLHttpRequest) { // Mozilla, Safari,...
		http_request = new XMLHttpRequest();
		if (http_request.overrideMimeType) {
			http_request.overrideMimeType('text/xml');
		}
	} else if (window.ActiveXObject) { // IE
		try {
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e) {}
		}
	}

	if (!http_request) {
		alert('Giving up :( Cannot create an XMLHTTP instance');
		return false;
	}
	//http_request.onreadystatechange = alertContents;
	//http_request.open('GET', url, true);
	//http_request.send(null);

	  http_request.onreadystatechange = alertContents;
	  http_request.open('POST', url, true);
	  http_request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
	  http_request.setRequestHeader("Content-length", parameters.length);
	  http_request.setRequestHeader("Connection", "close");
	  http_request.send(parameters);
}

function alertContents() {
	if (http_request.readyState == 4) {
		if (http_request.responseText.indexOf('Error -')==-1) {
			div_spec_frame.innerHTML = http_request.responseText;
		}
	}
}

function sw_mech(chairid, mechid) {
	div_spec_frame = document.getElementById("spec_frame");
	if (mechid!="?") {
		span_c_code = document.getElementById("c_code"); 
		span_c_code.innerHTML = mechid + chairid;
		span_c_img = document.getElementById("c_img"); 
		span_c_img.src = "images/chair_pic/" + mechid + chairid + ".jpg";
		div_pdf_link = document.getElementById("pdf_link");
		if (div_pdf_link) {
			div_pdf_link.href = "specs/" + mechid + chairid + "Spec.pdf";
		}
	}
	var data ="";
	data = "chairid=" + chairid + "&mechid=" + mechid;
	makeRequest('get_mech_spec.php',data );
}