function Comparison(PID) {
	_checked =  jQuery('input[name=ComparisonCheckBox_'+PID+']').attr("checked"); 
	_index = -1;
	for(i=0; i<ComparedProducts1.length; i++)
		if ( ComparedProducts1[i] == PID ) {
			_index = i;
			break;
		}
		if ( _checked ){
			if ( _index == -1 ) {
				ComparedProducts1.push( PID );
				ComparedProducts2.push( PID );
			}
		} else {
			if ( _index != -1 ){
				ComparedProducts1.splice( _index, 1 );
				ComparedProducts2.splice( _index, 1 );
			}
		}					
	}