Is teh player connected?

IsNumber(const string[])
{
	for (new i = 0, j = strlen(string); i < j; i++)
	{
	    if (string[i] > '9' || string[i] < '0') return 0;
	}
	return 1;
}
IsUserOnline(blah) {
	if(IsNumber(blah) && IsPlayerConnected(blah)) {
	    return 1;
 	}
 	if(!IsNumber(blah)) {
      	for (i = 0; i < MAX_PLAYERS; i++)
		{
			if ((IsPlayerConnected(i)) && (strcmp(playername, gPlayerName[i], true) == 0))
			{
			return 1;
			}
		}
 	}
	return 0;
}