Sub test_click
Dim binnum As String
Dim res As String
Dim N As Int
Dim Binlength As Int
Dim Binstart As Int
N = Rdisplay.Text 'Decimal number input
binnum = Bit.ToBinaryString (N) 'NOTE: Creates very long string if negative number
Binlength = binnum.Length
Binstart = Binlength - Min(Binlength, 12)
binnum = binnum.SubString2(Binstart, Binlength) 'Trims long string to 12 digits
Binlength = binnum.Length
'Adds comma every 4 digits
Dim j As Int = 0
For i = Binlength-1 To 0 Step -1
res = binnum.SubString2(i,i+1) & res
j = j + 1
If j Mod 4 = 0 AND j Mod 12 <> 0 Then
res = "," & res
End If
Next
binnum = res
Rdisplay.Text = binnum 'Binary number output formatted in to groups of four digits
End Sub