ASP.Net: Compiler Error Message: CS1525: Invalid expression term 'if'

hi

I want save data in session so I used below code:

        UserData user = new UserData
        {
            Name = Txtname.Text,
            State = DdlState.SelectedItem.Text,
            City = DdlCity.SelectedItem.Text,
            Mobile = TxtMob.Text,
            Tell = txttell.Text,
            Address = Txtaddu.Text,
            PostCode = TxtcodeU.Text,
            Email = TxtEmail.Text,
}

now I have radio button in page and I want if it checked it will save data in session:

     UserData user = new UserData
        {
            Name = Txtname.Text,
            State = DdlState.SelectedItem.Text,
            City = DdlCity.SelectedItem.Text,
            Mobile = TxtMob.Text,
            Tell = txttell.Text,
            Address = Txtaddu.Text,
            PostCode = TxtcodeU.Text,
            Email = TxtEmail.Text,
            if (Rborder.Checked)
        { order = "Orderd"},
}

but this error happen:

Server Error in '/' Application.
Compilation Error
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: CS1525: Invalid expression term 'if'

can you help me?

Best regards

Neda