add:  if (event.preventDefault) {  event.preventDefault(); } else {  return false; } 
context:                 xformsAddEventListener(textfield, "keypress", function(event) {                    if (event.keyCode == 10 || event.keyCode == 13) {                        xformsHandleValueChange(event);                        var span = getEventTarget(event).parentNode;                        xformsFireEvents(new Array(xformsCreateEventArray(span, "DOMActivate", null)));                    }                });
meta: 5390	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5390/b97dc1f5b0750425fffba90b357671c5ad146b56/xforms.js/buggy/src/examples/web/ops/javascript/xforms.js