Text from Form as Integer in Module Function - vb.net

Question

Working with Visual Basic in Visual Studio 2013. I need to take input from a textbox on form1 and use it as an integer in functions of a module. When I call one of the functions on form1 after a click event, I get an error for invalid arguments on the public function integers. How can I get the text passed to the module and then treated as an integer?
This is what I have on form1. This worked okay on the last project, which required the calculations to be performed and displayed only on form1. This project requires calculations to be performed in a module I created, and then displayed in labels on form2. (I'm still very new to this).
'Define inputs as public variables
Public intNumber1 As Integer
Public intNumber2 As Integer
'Create Function to validate inputs as integers
Public Function ValidateInputFields() As Boolean
'Try to convert each input to integer. If not, return error message, clear input, and return focus
If Not Integer.TryParse(txtNumber1.Text, intNumber1) Then
MessageBox.Show("Please enter only whole numbers.")
txtNumber1.Clear()
txtNumber1.Focus()
Return False
End If
If Not Integer.TryParse(txtNumber2.Text, intNumber2) Then
MessageBox.Show("Please enter only whole numbers.")
txtNumber2.Clear()
txtNumber2.Focus()
Return False
End If
Return True
End Function
This is the error message I get:
Error 1 Argument not specified for parameter 'intNumber1' of 'Public
Function AddInt() As Integer'.
This is the function I've written in the module:
'Create function to pass the values and add
Public Function AddInt(ByVal intNumber1 As Integer, intNumber2 As
Integer) As Integer
'Define intSum
Dim intSum As Integer
'AddInt adds numbers 1 and 2
intSum = intNumber1 + intNumber2
'Return the result
Return intSum
End Function

Answer 1

Text from a TextBox will be of type String and you need to convert it to an integer after checking whether its content can be safely interpreted as a number.
Something like this :
Dim num As Integer
If Not Integer.TryParse(TextBox1.Text, num) Then
'... it's not an integer, so don't try to use it
Else
'... call method using "num" as your integer parameter
End If

Answer 2

This is how I finally got my function calls to work correctly:
Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles
btnAdd.Click
'create instance for results form and define sum variable
Dim frmResults As New Results
Dim intSum As Integer
'If inputs are valid, display the integer sum on results form
If ValidateInputFields() Then
'Call Add Integer function from module
intSum = AddInt(intNumber1, intNumber2)
'Send answers to Results form and display
frmResults.lblNumber1Result.Text = intNumber1.ToString()
frmResults.lblOperatorResult.Text = "plus"
frmResults.lblNumber2Result.Text = intNumber2.ToString()
frmResults.lblEqualsResult.Text = intSum.ToString()
frmResults.ShowDialog()
End If
Everything worked once I added the (intNumber1, intNumber2) right after the function call of AddInt.
The ValidateInputFields() function is the TryParse method that #mcrimes was helping me with earlier. This did handle any non-numeric inputs or blanks left as it did in my previous project.
Thanks again #Jonathan and #mcrimes for all of your help.