Run an xpath expression against the current document

nice_xpath.js

function nice_xpath(xp) { 
    var x = document.evaluate(xp,  document.documentElement, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE, null, null); 
    if (x) { 
        var node = x.iterateNext();
        while (node) {     
            console.log(node); 
            node = x.iterateNext();
        }
    }
}
var xp = ".//*[self::input | self::textarea][(./@id = //label[contains(normalize-space(string(.)), user_password)]/@for)]";

nice_xpath(xp);