Not found .txt file causing my program to crash

Question

Im using VB6. In Form.Load I make the text found in C:\test.txt fill Text1.text. My problem is if the file C:\test.txt doesn't exist, my program just errors. How can I make it so that I get a MsgBox or other notification if the file is missing, instead of a program crash? (So that I can continue on with the program, but just be notified that the file isn't there) Here's the code I'm using:

nFileNum = FreeFile

Open "C:\test.txt" For Input As nFileNum
lLineCount = 1

    Do While Not EOF(nFileNum)
       Line Input #nFileNum, sNextLine
       sNextLine = sNextLine
       sText = sText & sNextLine
    Loop

Text1.Text = sText
Close nFileNum

Answer 1

Try

nFileNum = FreeFile

Open "C:\test.txt" For Input As nFileNum

If (nFileNum Is Nothing) Then
    MsgBox "Hello there!"
Else
    lLineCount = 1

        Do While Not EOF(nFileNum)
           Line Input #nFileNum, sNextLine
           sNextLine = sNextLine
           sText = sText & sNextLine
        Loop

    Text1.Text = sText
    Close nFileNum
End If

Answer 2

You need to add Error Handling to your code. Then check for the error message or error code, and then decide to display a warning message or not.

On Error GoTo err_check
nFileNum = FreeFile 

Open "C:\test.txt" For Input As nFileNum 
lLineCount = 1 

    Do While Not EOF(nFileNum) 
       Line Input #nFileNum, sNextLine 
       sNextLine = sNextLine 
       sText = sText & sNextLine 
    Loop 

Text1.Text = sText 
Close nFileNum

Exit Sub

err_check:
'Check error code/message and display warning message box here