var PDFrequest;

function pdfCheck(){
	if (window.XMLHttpRequest) PDFrequest = new XMLHttpRequest();
	else if (window.ActiveXObject) PDFrequest = new ActiveXObject("Microsoft.XMLHTTP");
	PDFrequest.open('GET', "pdf.txt", true);
	PDFrequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
	PDFrequest.onreadystatechange = insertPDF;
	PDFrequest.send("");
}

function insertPDF(){
	var button = document.getElementById("PDFButton");
	var dropdown = document.getElementById("tocnav");
	if (PDFrequest.readyState == 4 && PDFrequest.status == 200) {
		button.value = "PDF";
		dropdown.style.width = (dropdown.offsetWidth - 40) + "px";
		button.style.display = "inline";
		
	}
	else if(PDFrequest.readyState == 4){
		// do nothing, the pdf isn't there.
	}
}