var hide= false;
function toggleRows(tableId, numRowsToHide, tag){
	var tbl = document.getElementById(tableId);
	var vStyle = (hide)?"none":"";
	var len = tbl.rows.length;
	var topSpot = len-numRowsToHide;
	for(i=len-1; i>=topSpot; i--){
		tbl.rows[i].style.display = vStyle;
	}
	if(hide) {
		tag.innerHTML = "Expand";
	} else {
		tag.innerHTML = "Collapse";
	}
	hide= !hide;
}