var chkSubscribed = "CP2"; GM_log("CP1"); GM_log(chkSubscribed); //Check if already subscribed to thread chkSubscribed = document.evaluate( "//td[@class='s1']/.." ,document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null ).singleNodeValue.textContent.match('SUBSCRIBED'); GM_log("CP3"); GM_log(chkSubscribed); //If subscribed, mark post as read if (chkSubscribed == "SUBSCRIBED") { markReadBox = document.getElementById("modesu"); markReadBox.click(); } prevbutton = document.getElementById("post"); prevbutton.click();