[Luicy.]

Here:

PHP Code:

CMD:skin(playerid, listitem, response, dialogid, inputtext[]) 
{ 
    ShowPlayerDialog(playerid, 1, DIALOG_STYLE_INPUT, "Skin Change", "Enter the skin id you wish to have below", "Confirm", "Cancel"); 
    if (dialogid == 1) 
    { 
        if(response) 
        { 
            new skinid, message[64]; 
            skinid = strval(inputtext); 
            if(skinid < 0 || skinid > 299) 
            { 
                SendClientMessage(playerid, 0xFFFFFFFF, "SERVER: Skin id may be between 0 and 299."); 
            } 
            else 
            { 
                SetPlayerSkin(playerid, skinid); 
                format(message, sizeof(message), "SERVER: You have changed your skin id to %d.", skinid); 
                SendClientMessage(playerid, 0xFFFFFFFF, message); 
            } 
        } 
    } 
    return 1; 
} 


You can't return before it's finished, and you used return twice, removed the first return. Now should it be reachable.

Edit:

PHP Code:

CMD:skin(playerid) 
{ 
    ShowPlayerDialog(playerid, 1, DIALOG_STYLE_INPUT, "Skin Change", "Enter the skin id you wish to have below", "Confirm", "Cancel"); 
    return 1; 
}  
public OnDialogResponse(playerid, dialogid, response, listitem, inputtext[])
{
    if(dialogid == 1) 
    { 
        if(response) 
        { 
            new skinid, message[64]; 
            skinid = strval(inputtext); 
            if(skinid < 0 || skinid > 299) 
            { 
                SendClientMessage(playerid, 0xFFFFFFFF, "SERVER: Skin id may be between 0 and 299."); 
            } 
            else 
            { 
                SetPlayerSkin(playerid, skinid); 
                format(message, sizeof(message), "SERVER: You have changed your skin id to %d.", skinid); 
                SendClientMessage(playerid, 0xFFFFFFFF, message); 
            } 
        } 
    }
} 


Read the reply above me.