[AhmedMohamed]

Check this out:
https://sampwiki.blast.hk/wiki/Tolower

Is that what you need?

pawn Код:

public OnPlayerText(playerid, text[])
{
new string1[128],string2[128];
for(new i=0;i<strlen(text);i++) string2[i]=tolower(text[i]);
format(string1, sizeof(string1), "Hi %s", string2);
SendClientMessage(playerid, 0xFFFFFF, string1);
return 1;
}