Grease Monkey script + XPath

Question

How do i set the XPath to a Grease Monkey script

//Beautifying all the links....
var allLinks, thisLink;
allLinks = document.evaluate(
    '//a[@href=starts-with(name(),www.elakiri.com)]',  //a[@href=contains(name(),'www.elakiri.com')]   ////a[@href]  //*[starts-with(name(),'B')]
    document,
    null,
    XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE,
    null);

for (var i = 0; i < allLinks.snapshotLength; i++) {
    thisLink = allLinks.snapshotItem(i);
    //removing all the underlines
    thisLink.style.textDecoration = 'none';
}

This small script will underline all the links in any web page, but I want to do this to a specific website as mentioned. How do I do that, some people say that I need to use XPath but I do not have any experience on XPath. Please give me a clue.