Sort array by properties

sort-array.js

/*
* property: sort by property (name) - type: string 
* property2: then sort by property2 (name) - type: string - optional
* areNumbers: Are property and property2 numbers? - type: boolean - optional
*/
Array.prototype.sortBy = function(property, property2, areNumbers) 
{
  return this.sort(function(a,b) 
	{ 
		var valueA = areNumbers ? 0 : "";
		var valueB = areNumbers ? 0 : "";
		if (property)
		{
			valueA = areNumbers ? 
						(a[property] && !isNaN(a[property]) ? +a[property] : Number.MIN_SAFE_INTEGER) : 
						(a[property] ? a[property] + "" : "").toUpperCase();

			valueB = areNumbers ? 
					(b[property] && !isNaN(b[property]) ? +b[property] : Number.MIN_SAFE_INTEGER) :
					(b[property] ? b[property] + "" : "").toUpperCase();
			
			if (property2)
			{
				var valueA2 = areNumbers ? 
							(a[property2] && !isNaN(a[property2]) ? +a[property2] : Number.MIN_SAFE_INTEGER) :
							(a[property2] ? a[property2] + "" : "").toUpperCase();

				var valueB2 = areNumbers ? 
							(b[property2] && !isNaN(b[property2]) ? +b[property2] : Number.MIN_SAFE_INTEGER) :
							(b[property2] ? b[property2] + "" : "").toUpperCase();
				
				if (valueA == valueB)
					return (valueA2 < valueB2) ? -1 : (valueA2 > valueB2) ? 1 : 0;
				else 
					return (valueA < valueB) ? -1 : (valueA > valueB) ? 1 : 0;
			}
			else 
			{
				return (valueA < valueB) ? -1 : (valueA > valueB) ? 1 : 0;
			}
		}
		else 
		{
			valueA = areNumbers ? 
					(a ? +a : Number.MIN_SAFE_INTEGER) :
					(a ? a + "" : "").toUpperCase();
			valueB = areNumbers ? 
					(b ? +b : Number.MIN_SAFE_INTEGER) :
					(b ? b + "" : "").toUpperCase();
		}

		return (valueA < valueB) ? -1 : (valueA > valueB) ? 1 : 0;
 	});
}