/*
|| JavaScript by Shannon McPherson, 2006
|| mcphersonz@gmail.com
*/


var currentRow   = 0;


// Generate button links in 'button_td' HTML element:
function generate_row_buttons(){
  var link_prev =  "<a href='#' onClick='rowToggle(-1);'><img id='row_prev_enabled' style='display:none;' src='../images/arrow_up_enabled.gif' border=0><img id='row_prev_disabled'   style='display:none;' src='../images/arrow_up_disabled.gif' border=0></a>";
  var link_next =  "<a href='#' onClick='rowToggle(1);'><img id='row_next_enabled'  style='display:none;' src='../images/arrow_down_enabled.gif' border=0><img id='row_next_disabled' style='display:none;' src='../images/arrow_down_disabled.gif' border=0></a>";
  new Insertion.Bottom('button_td', link_prev); 
  new Insertion.Bottom('button_td', link_next); 
  updateButtonImages(0);
}


// user clicked row on a rowToggle link....
// Display appropriate row from from within "thumbnail_td" HTML element:	
function rowToggle(e){
  var navList         = $('thumbnail_td').getElementsByTagName('div');
  var numRows         = navList.length;
  currentRow = currentRow+e;
  if (currentRow <= 0) currentRow = 0;
  if (currentRow >= numRows) currentRow = numRows -1;
  for (var x = 0; x < numRows; x++){Element.hide(navList[x]);}
  Element.show(navList[currentRow]);
  updateButtonImages(currentRow); 
}


function updateButtonImages(currentRow){
  var navList         = $('thumbnail_td').getElementsByTagName('div');
  var numRows         = navList.length;
  if (numRows>1){
    // Swap arrow buttons if at beginning or end of rows:
    if (currentRow == 0) {Element.hide('row_prev_enabled'); Element.show('row_prev_disabled');}
    else {Element.hide('row_prev_disabled'); Element.show('row_prev_enabled');}
    if (currentRow == numRows-1) {Element.hide('row_next_enabled'); Element.show('row_next_disabled');}
    else {Element.hide('row_next_disabled'); Element.show('row_next_enabled');}
  }
}