function FormHelp() {
	this.infoElement = null;
}
FormHelp.prototype = {
	showInfo: function(trElement) {
		if (trElement == this.infoElement) return;
		this.hideInfoElement();

		if (trElement.childNodes.length != 3) {
			this.infoElement = null;
			return;
		}
		this.infoElement = trElement.childNodes[2];
		this.infoElement.style.visibility = 'visible';
	},
	
	hideInfoElement: function() {
		if (this.infoElement == null) return;
		this.infoElement.style.visibility = 'hidden';
		this.infoElement = null;
	},
	
	setTable: function(table) {
		var lthis = this;
		var rows = table.getElementsByTagName('tr');
		for (i = 0; i < rows.length; i ++) {
			rows[i].onmouseover = function() { lthis.showInfo(this); };
		}
	}
}