VB Check a Only Exactly Number in Textbox - vb.net

Question

Take a look at this picture. - http://www.imagebam.com/image/f544011007926944
I want to check in Textbox1, in the textbox2 enter the number and if there is that number I will appear in another text box. the problem occurs when in textbox1 there are numbers like 10,11, if I enter textbox2 number 1 then it will be taken as such, it will appear as if there is the number 1. I will only use for numbers from 1 to 80 .
where am I wrong?
' Split string based on space
Dim textsrtring As String = TextBox1.Text
Dim words As String() = textsrtring.Split(New Char() {" "c})
Dim found As Boolean = False
' Use For Each loop over words
Dim word As String
For Each word In words
If TextBox2.Lines(0).Contains(word) Then
found = True
If CheckVar1.Text.Contains(word) Then
Else
CheckVar1.Text = CheckVar1.Text + " " + TextBox1.Text()
End If
End If

Answer 1

So I think I know what you want. Your issue is the Compare Function on a String is comparing string literals and not numbers '11' contains '1' and '1' for Compare will return true that it contains a '1' in it. You need to convert the strings to numbers and then compare the numbers to each other.
Private Sub CompareNumbers()
'First Textbox that is to be used for compare
Dim textBox1Numbers As List(Of Integer) = GetNumbersFromTextLine(TextBox1.Text)
'Second Textbox that is to be used for compare
Dim textBox2Numbers As List(Of Integer) = GetNumbersFromTextLine(TextBox2.Text)
'Union List of Common Numbers (this uses a lambda expression, it can be done using two For Each loops instead.)
Dim commonNumbers As List(Of Integer) = textBox1Numbers.Where(Function(num) textBox2Numbers.Contains(num)).ToList()
'This is purely for testing to see if it worked you can.
Dim sb As StringBuilder = New StringBuilder()
For Each foundNum As Integer In commonNumbers
sb.Append(foundNum.ToString()).Append(" ")
Next
MessageBox.Show(sb.ToString())
End Sub
Private Function GetNumbersFromTextLine(sTextLine As String) As List(Of Integer)
Dim numberList As List(Of Integer) = New List(Of Integer)()
Dim sSplitNumbers As String() = sTextLine.Split(" ")
For Each sNumber As String In sSplitNumbers
If IsNumeric(sNumber) Then
Dim iNum As Integer = CInt(sNumber)
If Not numberList.Contains(iNum) Then
numberList.Add(iNum)
End If
Else
MessageBox.Show("Non Numeric Found in String :" + sTextLine)
End If
Next
Return numberList
End Function