integer position;
string notecard = "notecard_name"
key query;

default
{
    state_entry()
    {
        if(llGetInventoryType(notecard) == INVENTORY_NOTECARD)
            query = llGetNotecardLine(notecard, position);
        else
            llOwnerSay(notecard + " is not a notecard in the object's inventory.");
    }
    dataserver(key request, string data)
    {
        if(query == request)
        {
            if(data == EOF)
            {
                //End of notecard!
            }
            else
            {
                //Do something with the data
                //Increase the position variable and
                ++position;
                //Continue reading the next lines.
                query = llGetNotecardLine(notecard, position);
            }
        }
    }
}