Hello Jagat,
Thank you for writing.
The assembly that needs to be referenced is
Telrik.WinControls.UI.dll, and the namespace of
RadMessageBox is
Telerik.WinControls. Please refer to this
help article, which demonstrates how to make use of this compoenent.
I hope the provided information addresses your question. Should you have any other questions, do not hesitate to contact us.
All the best,
Stefan
the Telerik team
Q1’11 SP1 of RadControls for WinForms is available for
download; also available is the Q2'11
Roadmap for Telerik Windows Forms controls.