/*
 *		Javascript code for landing page
 */

String.prototype.trim = function() 
{ 
	return this.replace(/^\s+|\s+$/, ''); 
};

function startup
(
	error
)
{
	options_setup();
	land_reprice();
	options_change();
	goto(error);
}

function goto(message)
{
	if(message.length > 3)
	{
		location.href='#fb_target';
	}
}

function land_reprice()
{
	var height_string = document.getElementById("land_height").value;
	var width_string = document.getElementById("land_width").value;

	var valid = validate_dimension(height_string, "Height");
	valid = validate_dimension(width_string, "Width") && valid;
	
	if (valid)
	{
		var height = parse_value(height_string);
		var width = parse_value(width_string);
		
		document.getElementById("option_input_area").value = height * width;

		options_change();
	}
}

function validate_dimension
(
	string,
	title
)
{
	var result = true;
	var test = /(^\s*\d+\s*$)|(^\s*\d+\.\d*\s*$)/
	
	if (!test.test(string) || parse_value(string) < 0)
	{
		alert(title + " " + string + " is not a valid number");
		
		result = false;
	}
	
	return result;
}

function parse_value
(
	string
)
{
	return parseFloat(string.trim());
}