text: (function() {	
  	
  	// we need this for the HTML5 tests in IE
  	document.createElement("header");
  
  	// determine which selector engine to use for the tests
  	var selectedEngine = window.selectedEngine = (location.search == "") ? defaultEngine : unescape(location.search.substring(9));
  
  	// write a script tag to include the required selector library
  	document.write("<script src='" + selectedEngine + "'></scr" + "ipt>");
  
  	// hide the page so it doesn't jump around while we set test parameters
  	document.documentElement.style.marginTop = "-10000em";
  
  	// build the options menu 
  	window.onload = function() {
  		if (/*@cc_on!@*/false) { // IE only!
  			// if the test is being launched over the 'file' protocol, show a warning message...
  			if (window.location.protocol == "file:") {
  				var tests = document.getElementById("tests");
  				var warning = document.createElement("p");
  				warning.innerHTML = "Selectivizr cannot be run from the file system. Please ensure this test is served from a web server (IIS, Apache etc.)";
  				tests.parentNode.replaceChild(warning, tests);
  			} else {
  				var engineInput = document.getElementById("library");
  				for (var engine in engines) {
  					var optGroup = document.createElement("optgroup");
  					optGroup.setAttribute("label", engine);
  					for (var version in engines[engine]) {
  						var option = document.createElement("option");
  						option.value = engines[engine][version];
  						option.appendChild( document.createTextNode(engine + " " + version));
  						optGroup.appendChild(option);
  					}		
  					engineInput.appendChild(optGroup);
  				}
  				engineInput.value = selectedEngine;
  			}
  		}
  	
  		// test the :target pseudo-class
  		location = "#target";
  		
  		// test the :focus UI pseudo-class
  		document.getElementById("focus").focus();
  	
  		// show the page
  		setTimeout( function() { document.documentElement.style.marginTop = 0; }, 10);
  	}
  }());