var haystackText = "";
function findMyText(needle, replacement) {
     if (haystackText.length == 0) {
          haystackText = document.getElementById("page-body").innerHTML;
     }
     var match = new RegExp(needle, "ig");     
     var replaced = "";
     if (replacement.length > 0) {
          replaced = haystackText.replace(match, replacement);
     }
     document.getElementById("page-body").innerHTML = replaced;
}

function rep() {
findMyText('khilana','<font color=#FA3597 >khilana</font>');
}