function open_flowcalc( query_string ) {
	var opt = 'width=500,height=450,location=yes,resizable=yes';
	var url = '/products/flowcalc/';
	
	if( query_string != null ) {
		url += '?' + query_string;
	}
	
	var win = window.open( url, '_blank', opt );
	win.focus();
}

function parse_query_string() {
	var param        = new Object();
	var query_string = location.search;
	
	if( query_string == '' ) {
		return param;
	}
	
	var param_ary = query_string.substr( 1 ).split( '&' );
	
	for( var i = 0; i < param_ary.length; ++i ) {
		var ary = param_ary[i].split( '=' );
		param[ ary[0] ] = ary[1];
	}
	
	return param;
}