How do I make a loop only by using a command button and textbox (vb6)

public string ConvertToText(string text)
        {
            int a;
            string output=string.Empty;
            if(Int32.TryParse(text,out a))
            {
                for(int i=1;i<=a;i++)
                {
                    for(int j=1;j<=i;j++)
                    {
                        output +=Convert.ToString(j);
                    }
                    output+="\n"; // here you can replace with specific new line character of vb6
                }
            }
            return output;
        }

Public Function ConvertToText(ByVal text As String) As String
       Dim a As Integer
       Dim output As String = string.Empty
       If Int32.TryParse(text, a) Then
           Dim i As Integer = 1
           Do While (i <= a)
               Dim j As Integer = 1
               Do While (j <= i)
                   output = (output + Convert.ToString(j))
                   j = (j + 1)
               Loop
               output = (output + ""& vbLf)
               ' here you can replace with specific new line character of vb6
               i = (i + 1)
           Loop
       End If
       Return output
   End Function