Hey how do i set the icon on a form?

i found this
Code:
System.Resources.ResourceManager resources = new System.Resources.ResourceManager(typeof(parent));
this.Icon = ((System.Drawing.Icon)(resources.GetObject("$this.icon")));
But i dont understand it and it doesnt work.

Heres how im compiling it
Code:
csc /r:Interface/Interface.dll /t:winexe /win32icon:parent.ico parent.cs

Thanks