I am working on an ASP .Net C# project and I am a beginner in web programming. I get the below error at runtime:

> 
> Object reference not set to an instance of an object.
> 
> 
> 

Below is my code:

```
protected void Page_Load(object sender, EventArgs e)
{
    txtUsername.Focus();
    if (cmbThemes.SelectedItem.Text=="Red")
    {
        pnlSignin.Border.BorderColor = Color.Orange;
    }
}

```

`cmbThemes` is a `ComboBox`.

Thanks in advance.