Luhn Validation Logic on JavaScript

Luhn Validation

function luhnValidate(input){
	var tmp = 0,i,il,cur,head;
	for(i=0,il=input.length;i<il;i++){
		cur = parseInt(input[il-i-1])*(i%2 ? 2 : 1);
		head = Math.floor(cur/10);
		tmp += head + (cur - head *10);
	}
	return !(tmp % 10);
}