Password textbox getting problem in VB.Net

Question

Hi,

 I have created password field for new and confirm password in password mode in VB.Net, while saving textbox become empty but after updation textbox is not clear. i have used code - 

txtUserProfilePassword.Attributes.Add("value", txtUserProfilePassword.Text.Trim())

txtUserProfileConfirmPassword.Attributes.Add("value", txtUserProfileConfirmPassword.Text.Trim())

after submitting i am using code like - 

txtUserProfilePassword.text = ""

or

txtUserProfilePassword.text = string.empty

but still textbox are not clear....

 what code i should write for this??