cheap solution is to use thin-film used for food packaging. Use it and throw till its last. Its stick to the screen of the laptop well, if put perfectly u cannot recognise it on first site. We generally use it on our store for covering the laptops on display with thin-film , to keep it safe from dust and scratches....
Ofcourse u can go for Laptop Screen guard, if they are available..
Get the Zagg invisible shield .I am using the same from the past 8 months.Its an awesome product.One cant even make out there is a shield on the laptop.
All the Zagg screens are custom cut ones.Try mailing zagg that they haven't listed the Shield for your model .They will help you out.I got a product similar way.They area a bit expensive but worth the moolah.
Edit :They do have the Inspiron 1420.Which is your model
Before you purchase PM me i will try looking out for coupons.I guess i do have the 50% off coupon
Could you please give me a link where Zagg provides LCD protection for laptops?
I checked out the Zagg shield but their site states:
Full Body Coverage for Laptops
Full body coverage for laptops protects the top, bottom, and wrist rest. Please note, we currently do not make invisibleSHIELDs to cover soft LCD screens, such as on laptops.