var lastItemImageNo = -1;
var curItemImageNo = -1;
function showhideImageBlock( imgno, action )
{
  for ( var i = 1; i <= 3; i++ )
  {
  	var obj = document.getElementById('tr_'+i+'_'+imgno)
  	if ( obj )
			obj.style.display= (action=='hide'?'none':'');
	}
}

function checkImageBlock( imgno )
{
  if ( imgno == lastItemImageNo )
  	return;
	var obj =	document.getElementById('inp_noimg_'+imgno);
	if ( obj )
		showhideImageBlock( imgno, obj.checked?"hide":"show" );
}

function checkUploadBtn( fileInput, imgno )
{
	var obj = document.getElementById("btnDoUpload_"+imgno);
	if ( obj )
		obj.disabled = (fileInput.value.length == 0);
}