Asad FM101 :
I want to build a gaming system that is less then 400 $ with scope of upgrading cpu. like from intel pantium g2020 to core i5.. can you suggest me a motherboard which can support a number of processors.
This $400 build is probably the best "bang for the buck" although it is $4 over your budget and I must warn that the power supply will have to be upgraded with future upgrades due to it being an OEM power supply which lack power and can die with higher wattages so I'd recommend a 600 or 850 Watt corsair or seasonic power supply when you get an i5 down the road, and this supports an i5-4670, but you can't overclock with this motherboard. well, here it is:
http://pcpartpicker.com/user/ManagedMonkey/saved/Jhnypg
One last thing, get a new graphics card if you want higher performance, my favorite with an i5 today is the gtx 750 Ti by asus or evga.