Multiple inputboxes one test for null input - vba

Question

Ok, so I have a series of input boxes pop up for the user and I know I want to check if the user hits cancel or "X" then I will have to check its return value.
EX answer = inputbox("lelele") if answer = "" then end else end if.
My problem is I have 4 input boxes in a row and I don't want to have to do a separate if statement for every input box so is there a way I can check all three in some sort of try catch block or while loop?
Below is the code I am actually using. Keep in mind that I am trying to catch a cancel every step along the way, so any time anyone clicks cancel the program immediately stops running.
'column you want to first select for copying
ColSelect = InputBox("which column do you want to select ColCopyFrom")
'the column you are comparing it to
ColCompare = InputBox("which column do you want to compare to ")
'where you are copying data from
ColCopyFrom = InputBox("which column do you want to copy data ColCopyFrom")
'where you are copying data to
ColCopyTo = InputBox("which column do you want to copy data to")
<
This is what I want to do for every box
if ColSelect = "" then
exit
else
'do nothing
end if
if ColCompare = "" then
exit
else
end if

Answer 1

You could wrap the inputbox into a function passing the prompt as a parameter like this and use END to break:
Function myInputBox(prompt As String) As String
Dim ib As String
ib = InputBox(prompt)
If ...
'... do some checking here
Else
End 'stop dead here
End if
myInputBox = ib
End Function
On the other hand, you might think about using a UserForm instead for enhanced usability.

Answer 2

Could you create a function and call it to check for each input? By creating a function once you can call upon it as many times as necessary, in your case 4 times. When you call the function you can then substitute the variable to check against
'first inputbox
Call checker(ColSelect)
'second input box
Call checker(ColCompare)
'etc
This is the function to check and you will see the variable name is cancel. This will take the variable entered (in the example ColSelect) and then give it a new name. This can be anything you like
sub checker(cancel)
if cancel = "" then
exit
else
'do nothing
end if
end Sub