how to make a form mdi c#

C# winform has multiple document interface facility .

to make a form mdi just go to form properties and make iscontiner =true it will be a multiple documents interface .

to call child form in mdi form write the following code

myform newmyform=new myform() ;

newmyform.mdiparent=this ;

newmyform.show() ;

to call form in child chil form

myform newmyform=new myform() ;
newmyform.mdiparent=this.mdiparent ;
newmyform.show()