How Do I Enable Or Diaable Textbox For Two Different Users

So, basically you want to perform something after identifying the Role of User.

I assume, that you are having some mechanism to identify Role of a User. For that you might have a Column in User Table or a separate table altogether for User Role.

Just retrieve that Role value from Database, while User Logs in. Then try to run a logic based on that. Something like below.

string userRole = roleRetrievedFromDatabase; // Retrieve this from Database

if(userRole.Equals("manager"))
{
    manager.Enabled = true;
    employees.Enabled = false;
}
else if (userRole.Equals("employee"))
{
    employees.Enabled = true;
    manager.Enabled = false;
}