Using Javascript to check If a page doesn't contain a certain word

[takiramski]

\[code\]var xpathResult = document.evaluate("(//text()[contains(., 'WORD')])[1]", document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null);var node=xpathResult.singleNodeValue;if (node==null)\[/code\]This checks for a string.Is there an opposite of it?