using System;
public static class StringExtension
{
public static byte[] ToAscii(this String s)
{
byte[] retval = new byte[s.Length];
for (int ix = 0; ix < s.Length; ++ix)
{
char ch = s[ix];
if (ch <= 0x7f) retval[ix] = (byte)ch;
else retval[ix] = (byte)'?';
}
return retval;
}
}