How to call ME21n Screen in webdynpro once you click any button

Hi exports,

I have created one webdynpro application..In first view i have one button which have action...Once i click that button

it should go to next view where it should diaplay standard Transaction ME21n screen..where i need to enter all PO details..finally PO should be created auotomatically like normal SAP...

Can anybody plz help me how can i acheive this?

Thanks & regards,

Praveena.