Search:

TextBox.Text = "" ---> Text Box
List1.Clear ---> ListBox
Combo1.Clear ---> ComboBox

How about this one:

Dim the first as Integer
Dim theSecond as Integer
dim theThird as Integer
dim theFourth as Integer

the first = 15
thesecond = 3
if the first > theSecond then

Do you want to print the code, or you want the code to print? I don't know what the code in VBNET, but in VB6, it's Me.PrintForm

The flow is:-
Form ---> Object ---> Properties

So, it should be frmFriends.txtPhone.Text

But if you are referring in the same form, then ignore the Form, just txtPhone.Text.

1) You need to know:
i. How much gas per mile OR
ii. How much mile per 1 liter gas?
2) Then, use basic arithmetic to solve it (+,-,/,*).

Check this sample.
1) [ A Simple Calculator With Error Handling ] by JamesJD
2) [;)A Simple Calculator (Great for beginners to VB);)] by Steven Jacobs

1) Rename your textbox to Text1, Text2, Text3, Text4 and Text5.
2) Double click List1. The code should be like this:-
Private Sub List1_Click()
List1.ListIndex=0
Text1.Text=List1.Text...

You can find a sample code here.
[;)A Simple Calculator (Great for beginners to VB);)] by Steven Jacobs

It is illegal to share it directly to you. You need to purchase it. But, you can find it at
http://www.planet-source-code.com/vb/scripts/ShowCode.asp?txtCodeId=68020&lngWId=1

*Just helping...