Cannot implicitly convert type 'char' to 'bool'

[dipique]

I have the following code:

if (e.KeyChar = (char)13)
    {
        SomeFunction(params);
    }

When the program complies I get the following error:

(231): Cannot implicitly convert type 'char' to 'bool'

Any ideas why that might be? The code is in the following function:

private void nudWidth_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)

which is a Numeric UpDown control.

Dan