This line should be updated:
var Registration_group_1_Confirm_Spry = new Spry.Widget.ValidationTextField("Registration_group_1_Confirm_Spry", "none", { isConfirm:true , validateOn:["blur"]});
to:
var Registration_group_1_Confirm_Spry = new Spry.Widget.ValidationConfirm("Registration_group_1_Confirm_Spry", "Registration_group_1_password");
And then you'll have to add the spry confirm .js and .css files to your header. I've attached a copy of those files.