IE Firefox兼容Enter替代Tab的javaScript

IE Firefox兼容Enter代替Tab的javaScript

document.onkeydown=function(evt)              {               var isie = (document.all) ? true : false;               var key;               var srcobj;               if (isie)                {                  key = event.keyCode;                  srcobj=event.srcElement;                  }               else                {                  key = evt.which;                  srcobj=evt.target;                  }                               if(key==13 && srcobj.type!='button' && srcobj.type!='submit' &&srcobj.type!='reset' && srcobj.type!='textarea' && srcobj.type!='')                                  {                   if(isie)                    {                     event.keyCode=9;                    }                   else                    {                                            var el=getNextElement(evt.target);                             if (el.type!='hidden')                                 el.focus();                             else                                while (el.type=='hidden')                                    el=getNextElement(el);                                 el.focus();                             return false;                    }                  }               }                               function getNextElement (field) {                   var form = field.form;                   for (var e = 0; e < form.elements.length; e++) {                     if (field == form.elements[e])                         break;                    }                   return form.elements[++e % form.elements.length];                  }