Toggle control with dual function

Hi Guys,

I have a Javascript function that toggles a 'show/hide' table row:

//CONTROL

<a href="#" onclick="toggle('ROW 1, this)"><img src="../../Images/plus.gif" border="0" /></a>

HTML:

//JAVASCRIPT

function toggle(id, obj) {
   var matchingElements = new Array();
   
   if (document.getElementsByClassName) {
      matchingElements = document.getElementsByClassName(id);
   } else {
      var elements = document.getElementsByTagName("tr");
      for (i = 0; i < elements.length; i++) {
         if (elements[i].className == id) {
            matchingElements[matchingElements.length] = elements[i];
         }
      }
   }
   
    for (i = 0; i < matchingElements.length; i++) {
      toggleDisplay(matchingElements[i], obj);
   }
}

function toggleDisplay(element, obj) {
   if (element.style.display == "none") {
      element.style.display = "block";
      obj.innerHTML = "<img src=\"../../Images/minus.gif\" border=\"0\">";
   } else {
      element.style.display = "none";
      obj.innerHTML = "<img src=\"../../Images/plus.gif\" border=\"0\">";
   }
}

Code (markup):

Which works fine, but what I need is something like this:

Control 1:
Toggle - ROW 1 (+ Close ROW 2 (if visible))

Control 2:
Toggle - ROW 2

Is this a Javascript or PHP issue?