Javascript Math: get the distance between two points.

gistfile1.txt

/**
 * return the distance between two points.
 *
 * @param {number} x1		x position of first point
 * @param {number} y1		y position of first point
 * @param {number} x2		x position of second point
 * @param {number} y2		y position of second point
 * @return {number} 		distance between given points
 */
Math.getDistance = function( x1, y1, x2, y2 ) {
	
	var 	xs = x2 - x1,
		ys = y2 - y1;		
	
	xs *= xs;
	ys *= ys;
	 
	return Math.sqrt( xs + ys );
};