I'm fairly sure you need a HDMI cable to connect a laptop to a TV,
But as Mathepac said we don't know your connection types..
Sony vaoi should have a hdmi port..is your tv new?
This link will show you (Video tutorial)how to connect a pc.. to a tv with different types of connections available..look out for the hdmi part....same principal should apply to a laptop http://www.dummies.com/how-to/content/connecting-your-pc-to-your-hdtv.html
Just to add somthing, if your tv is a newish model - you will need need a DVI to HDMI cable. This will give you the best quality of picture.
If your tv hasnt a dvi connection, I am sure it has a VGA (blue) connector. All you need then is a male to male VGA cable.
Purchase these from ebay, if you can. I bought a TV from Harvey Norman last weekend, and they were selling HDMI cables for €99. I got one of ebay for €6. No difference...