function showTab(obj) {
  TabItemCount = 5;
  TabColorInactive = '#FFFFFF';
  TabColorActive = '#FFFFFF'
  TabItemFirstObj = 'SRD1';

  //RESET BGCOLOR
  for(i=1;i<=TabItemCount;i++) {
    document.getElementById('SRD' + i).setAttribute('bgcolor', TabColorInactive, 0);
  }

  //RESET BORDERS
  for(i=1;i<=TabItemCount;i++) {
    document.getElementById('SRD' + i).className = 'srdTabBorder cursorPointer';
  }

  //RESET TEXT
  for(i=1;i<=TabItemCount;i++) {
    document.getElementById('SRD' + i + 'Text').className = 'srdTabText';
  }

  //RESET ALL DIVs AS NONE/HIDDEN
  for(i=1;i<=TabItemCount;i++) {
    document.getElementById('LayerSRD' + i).style.display = 'none';
  }

  //SETS/RESETS THE FIRST TAB
  document.getElementById('SRD1').className = 'srdTabBorderBottom srdTabBorderFirst cursorPointer';

  //APPLY THE ACTIVE STYLE TO THE SELECTED TAB		
  document.getElementById(obj).setAttribute('bgcolor', TabColorActive, 0);

  if(obj == TabItemFirstObj) {
    document.getElementById(obj).className = 'srdTabBorderActive srdTabBorderFirst';
  } else {
    document.getElementById(obj).className = 'srdTabBorderActive';
  }
  document.getElementById(obj + 'Text').className = 'srdTabTextActive';
  document.getElementById('Layer' + obj).style.display = 'block';

  if(obj == 'SRD4') {
    document.getElementById('LayerMap').style.visibility = 'visible';
  } else {
    document.getElementById('LayerMap').style.visibility = 'hidden';
  }

  if(obj == 'SRD5') {
    document.getElementById('LayerAtt').style.visibility = 'visible';
  } else {
    document.getElementById('LayerAtt').style.visibility = 'hidden';
  }
}