Asp.net using c#

Question

Dear all,

{Kindly don't ignore my question. I will be very thankfull to you if you help me}

Hi friend i am doing project in Asp.net using c# code(front end).My backend( ms sql server). I am helpless kindly help me for my problem.(I am very new to this).

First I created One Student  registration form with the fields name,roll number, department,Branch,password.For Branch i kept one dropdownlist box that holds Msc and MCA.

Secondly I created login form with the fields user name and password. Roll number will be their user name for the student. The student use their rollnumber and password to proceed the third form.

I don't know how to write proper and correct codings for my third form So kindly help me.

My third form:

I designed  Form with two radio button,two dropdown list box, one text box.

1) Radio button1 is named as Msc and  Radio button2 is named as MCA.
2)Dropdown list1 holds sem1,sem2,sem3,sem4 and dropdown list2 holds sem1,sem2,sem3,sem4,sem5,sem6.
3)Dropdown list1 for Msc Radiobutton1 and Dropdown list2  for MCA Radiobutton2.

when a student login using their roll number and password they will get the third form.

Msc roll number starts with 216(but full roll number look like this 216111001...) and MCA roll number starts with 205(but full roll number look like this 205111001...)

1)*So when an Msc student login using their username(i.e., rollnumber) for that student  Radio button1 named  as Msc and Dropdown list1 holds sem1,sem2,sem3,sem4 must be visible 
*Radio button2  named as MCA and Dropdown list2 holds sem1,sem2,sem3,sem4,sem5,sem6 must be invisible
2)*If  MCA student login using their username(i.e., rollnumber) for that student  Radio button2  named  as MCA and Dropdown list2 holds sem1,sem2,sem3,sem4,sem5,sem6 must be visible 
*Radio button1  named as Msc and Dropdown list1 holds sem1,sem2,sem3,sem4 must be invisible

This the condition kindly send me codings for my problem i am struggling a lot.

I will be very much thankfull to you...