validate a date string in javascript

validDate.js

function isValidDate(date) {
	var parts = date.split('/');
	var month = parts[0];
	var day = parts[1];
	var year = parts [2];
 	year = Number(year);
 	month = Number(month);
 	day = Number(day)
    var d = new Date(date);
    if (d.getFullYear() != year 
    	|| (d.getMonth() + 1) != month 
    	|| d.getDate() != day) {
        return false;
    }
    return true;
}