2 rf modules

Hi, i can conect 2 arduinos to send text via rf, but how can i conect 2 arduinos with 2 differents rf modules, without have a problem with the comunication channel?

What do you mean by different rf modules?

Using 2 kits of rf modules 2 transmitter and 2 receiver, withouth having the problem of the same channel for sending and reciving data :s

Can you post a link to the modules?

sorry i was at school http://articulo.mercadolibre.com.mx/MLM-454542583-kit-modulos-rf-transmisor-y-receptor-433-mhz-_JM this it is

someone can help me with this :s

Your question makes no sense.
If what you mean is can I have a system where I can send data and receive data at the same time using those types of modules
the answer is no, you cant.
If you want to send data in both directions , you need better radio modules , such as Xbees or NRF24l01 .

those are bad news for me :s i just want to send data from one arduino to the other using one kit, and when the other arduino read some sensors he send it back to the other arduino using the different kit

OK, you will have to look at whether VirtualWire can operate in full duplex mode .
I dont think it can.
The problem with those cheap modules, is that you have to pre process the data with some program running in the Arduino to make them work reliably.
Most people use Virtualwire, but only for 1 way transmission.

thats bad for me :S but thanks bro