[ThePhenix]

You can do it using an input dialog, and check if the inputtext is numeric, after that you have to strval(inputtext); and finally you can perform a second check to know if the ID entered was valid or not.

PHP код:

http://wiki.sa-mp.com/wiki/ShowPlayerDialog 


PHP код:

public OnDialogResponse(playerid, dialogid, response, listitem, inputtext[])
{
        return 0;
} 


I don't know who made this function, but here it is:

PHP код:

IsNumeric(const string[])
{
        for (new i = 0, j = strlen(string); i < j; i++)
        {
                if (string[i] > '9' || string[i] < '0') return 0;
        }
        return 1;
}