Javascript:: حذف مقادیر تکراری از آرایه

var unique = function(origArr) {
    var newArr = [],
    origLen = origArr.length,
    found,
    x, y;
     
    for ( x = 0; x < origLen; x++ ) {
    found = undefined;
    for ( y = 0; y < newArr.length; y++ ) {
    if ( origArr[x] === newArr[y] ) {
    found = true;
    break;
    }
    }
    if ( !found) newArr.push( origArr[x] );
    }
    return newArr;
    }
     
    var myarray = ['jeffrey', 'allie', 'patty', 'damon', 'zach', 'jeffrey', 'allie', 'patty', 'damon', 'zach', 'joe'];
    myarray = unique(myarray);
    alert(myarray.join(', '));