How to find change password control from code behind and pass values usinc C# NET4.5

/* Good day all, i am using the drag and drop change password control on asp.net membership, my problem here now is i have my own salt which i will need to add from codebehind which i will need the old password and new password to carry... something like this.... */ protected void ChangePasswordPushButton_Click1(object sender, EventArgs e) { string cpass = "2_2'." + ChangePassword1.CurrentPassword; string Npass = "2_2'." + ChangePassword1.NewPassword; if(cpass != Npass) { //i want the membership password control to use the value in cpass to validate the old password and use //the Npass as the new password and store it... How do i do that... thanks.... I do appreciate your time } }