Ado Net Entity Framework

Question

i have a form in that i 3 texxtboxes  named Rollno,name,ageand course

and i have 2 class 1 for connection named MyDBConeection and 1 is for all data related class called student

in MyDbConnection I gave connection details

in my student class i gave  4 properties named Rollno,Name,Age,Course and corresponding methods

public int Getdetails

{

it will display all details in grid view

}

public dataset update ()

{

update the table

}

BUT i need is this

i have a button in my form called getdetails before update 

like this 

roll no - textbox 

then getdetails button

then name,age and course then update button

i want to display all details in my textbox while clicking on the getdetails button then update

plzz help...............