I'm trying to write my own Custom Validation attribute but i'm having some problems.

The attribute i'm trying to write is that when a user logs in, the password will be compared against the confirmation password.

namespace EventCompanion.Data.Attributes
{
public class ComparePassword : ValidationAttribute
{
    public string PasswordToCompareWith { get; set; }

    public override bool IsValid(object value)
    {
        if (PasswordToCompareWith == (string)value)
        {
            return true;
        }
       return false;
    }
}

Now my problem is when i'm trying to set the attribute like this in the model file:

 [Required]
    [ComparePassword(PasswordToCompareWith=ConfirmPassword)]
    public string Password { get; set; }


    [Required]
    public string ConfirmPassword { get; set; }
   }

I get the following error:

Error 1 An object reference is required for the non-static field, method,       or property 'Project.Data.Models.GebruikerRegistreerModel.ConfirmPassword.get'  

It seems that VS is not accepting the confirmpassword in the "PasswordToCompareWith=ConfirmPassword" part

Now my question:

What am i doing wrong?

Thanks in advance!!!