diff --git a/sorttable.js b/sorttable.js
index f571270..0c885c1 100644
--- a/sorttable.js
+++ b/sorttable.js
@@ -169,8 +169,10 @@ sorttable = {
     sortfn = sorttable.sort_alpha;
     for (var i=0; i<table.tBodies[0].rows.length; i++) {
       text = sorttable.getInnerText(table.tBodies[0].rows[i].cells[column]);
+
       if (text !== '') {
         if (text.match(/^-?[£$¤]?[\d,.]+%?$/)) {
+
           return sorttable.sort_numeric;
         }
         // check for a date: dd/mm/yyyy or dd/mm/yy
@@ -209,8 +211,8 @@ sorttable = {
     hasInputs = (typeof node.getElementsByTagName == 'function') &&
                  node.getElementsByTagName('input').length;
 
-    if (node.nodeType == 1 && node.getAttribute("sorttable_customkey") !== null) {
-      return node.getAttribute("sorttable_customkey");
+    if (node.nodeType == 1 && node.getAttribute("data-value") != null) {
+      return node.getAttribute("data-value");
     }
     else if (typeof node.textContent != 'undefined' && !hasInputs) {
       return node.textContent.replace(/^\s+|\s+$/g, '');