generate numbers between set values vb.net - vb.net

Question

I am creating a program to generate numbers between a list of values.
Problem I am having is if the first number stats with a smaller value than the second value it will create an error, such as 1000 and 32 will say it doesnt work, or 532 and 64
I do not understand why or how to fix it
Private Sub Generate_Click(sender As System.Object,
e As System.EventArgs) Handles Generate.Click
'Displays to enter correct information if lower is <=
If Upper.Text <= Lower.Text Or Lower.Text >= Upper.Text Then
List.Items.Clear()
List.Items.Add("Please enter correct info Upper # higher value than Lower #")
Else
'If Upper range is higher than lower range then display numbers until total value is displayed
List.Items.Clear()
Number.Text = ""
Dim i As Integer = Lower.Text
Do While i <= Upper.Text 'Loop generates the numbers between values specified
List.Items.Add(i)
i += 1
Loop
'Select a random value from the list generated
Dim myRandom As New Random
Dim b As Integer = List.Items.Count
Dim chosenItem As System.Object = List.Items.Item(myRandom.Next(b))
Number.Text = chosenItem.ToString
End If
End Sub

Answer 1

Basically you have to compare numeric value you are comparing string so it is happening.
And 'or' condition is not required in if statement so omit it.
please replace you code as follows.
if System.Convert.ToInt32(Upper.Text) <= System.Convert.ToInt32(Lower.Text) Then
List.Items.Clear()
List.Items.Add("Please enter correct info Upper # higher value than Lower #")
Else
List.Items.Clear()
Number.Text = ""
Dim i As Integer = Lower.Text
Do While i <= System.Convert.ToInt32(Upper.Text) 'Loop generates the numbers between values specified
List.Items.Add(i)
i += 1
Loop
'Select a random value from the list generated
Dim myRandom As New Random
Dim b As Integer = List.Items.Count
Dim chosenItem As System.Object = List.Items.Item(myRandom.Next(b))
Number.Text = chosenItem.ToString
End If

Answer 2

With the If clause, you are doing a string comparison on numerical values. You need to cast them to integer values. And you are doing the same comparison twice which is unnecessary. Also there is a simpler way of generating random numbers between two integers.
I would encourage you to code with the "Option Strict On" declaration at the top of the page. The compiler will alert you when you attempt to make implicit conversions of which there are several in your code.
Dim iMinimum As Integer = Integer.Parse(Lower.Text)
Dim iMaximum As Integer = Integer.Parse(Upper.Text)
If iMaximum <= iMinimum Then
Number.Text = "Please enter correct info Upper # higher value than Lower #"
Else
Dim randomObject As Random = New Random
Number.Text = randomObject.Next(iMinimum, iMaximum).ToString
End If