[Vlasenko Fedor]

nerv_, согласен +(не могу)

var a = [1,2,3];
var b = [1,2,3];
var c = [];
var d = [Array];
var e =[null];
function array_equal ( a, b ) {
    return a.every(function(el, i){
        return el === b[i];
    }, b);
}

alert(array_equal ( a, b ));
alert(array_equal ( a, c ));
alert(array_equal ( d, e ));