How should I compare?

var inn = document.thisItem.getInnovator();

var myI = new top.Innovator();
var userID = myI.getUserID();
alert (userID);


var body = "SELECT U.ID "
+"FROM innovator.[IDENTITY] I "
+"INNER JOIN innovator.MEMBER M ON I.ID = M.SOURCE_ID "
+"INNER JOIN innovator.[USER] U ON M.RELATED_ID = U.OWNED_BY_ID "
+"WHERE I.NAME = 'Sales' AND U.ID = '"+userID+"'";

var factors = inn.applySQL(body);
alert(factors);

var itemID = factors.getProperty("id");

if(itemID == "")
alert("pdf")
else
alert("no pdf");