Auto fill based on 2 sets of criteria

Auto fill based on 2 sets of criteria

I have a database started and have made some headway in Auto-fill.  My question is I want to create a form that will auto fill based on two sets of criteria.  Currently I have a script written that will will auto fill based on one criteria.  I want to be able to be able to auto fill based on the a Client ID and also the Product number (there might be the same product number for multiple clients, this is why I need the script to look at both criteria.

this is the script I currently have:

if (count(Extinguisher_Locator[Number == input.Number])  >  0)
{
    temp  =  Extinguisher_Locator  [Number == input.Number];
    input.MFR_Name = temp.MFR_Name;
    input.Last_Mnt = temp.Last_Mnt;
    input.Ext_Size = temp.Ext_Size;
    input.Type = temp.Type;
    input.MFR_Year = temp.MFR_Year;
    input.Date_of_Last_Mnt = temp.Date_of_Last_Mnt;
    input.Equipment_Location = temp.Equipment_Location;
}
else
{
    alert("Extinguisher number didn't match, please continue to add a new extinguisher to this location");
}

Thanks for any help in getting this accomplished