Is it possible to connect my laptop to a tv with only av no hdml port?

Buy one VGA to AV video converter. Connect it in between computer and TV, using AV cable.

If your laptop does not have a HDMI port then you need a VGA to HDMI converter. Connect this converter to your laptop and then connect it to the TV using a HDMI cable. You also need to connect the audio out port on the laptop to the audio in on the TV. You can get a combined audio input with some HDMI converters.
Check out this WEB site.
http://www.proaudiovisual.com.au/vga-to-hdmi-converter-adapter-and-upscaler-video-audio-full-hd-1080p/

Most Acer laptops have a Blue VGA Port for external monitor hookup. Does your TV aslo have such a port (most newer models should)? If so connect these and change display settings on Laptop.

Depends on type of input ports available on TV. Does it have AV ports? If yes, you need a serial port to AV adapter cable. An example is here: http://www.buy.com/retail/product.asp?sku=212966741&listingid=94897580

If the TV only has a coaxial cable input, you also need an RF modulator. An example can be seen here: http://www.radioshack.com/product/index.jsp?productId=2103095

The latter includes a modulator similar to old gaming consoles that modulates TV channel 3 or 4. You have to set the TV channel to one of those for it to work. In the former case (TV has AV inputs), you turn the TV channel to the "Line in" setting.

OK?

It is possible to connect your laptop to any LCD TV. For which you need to locate the external VGA port on your laptop. As your Laptop doesn't have S-Video port you would have to deal with the VGA port.
There are several adapters available in the market which can solve your problem:VGA to RCA orVGA to S-Video orDual VGA cable
Your LCD TV should be equipped with all the ports mentioned above that are:RCA (AV)S-VideoVGA In
But as I don't know the model Number of your TV I don't know whether your TV has S-Video or VGA ports but the RCA (AV) are the most common ones which I am pretty sure you would have.
Here are some pics of the cables.
^Dual VGA cable
^VGA to RCA or S-Video
You can buy these cables from the market and easily connect your system to the TV.
If you need further help, please feel free to contact me.

ur laptop has a S-video/TV-out (NTSC/PAL) port, which can be used 2 connect 2 a compatible TV or a AV reciver. try using a svideo cable

In order to connect your Laptop with Xbox 360, you will have to use the ethernet cable that came along with the Xbox 360,

For connecting the Xbox 360 to TV you would be having a HD AV cable if you have a Xbox 360 Pro model, you would have to insert one part of this cable with 3 colored wires red,blue and green to your composite video port behind your tv with similar color coding, and on the Xbox 360 HD AV cable you have an option to choose either TV or HD video output based on your TV make, also this cable has two more wires red and white meant for audio connectivity which would go to audio port behind TV with same color code ports

If you have got a normal AV cable with Xbox 360 then it would be a a wire with one single yellow colored wire for video and two wires Red and White for audio