How to connect PC HP 520 to Panasonic Viera LCD TV?

I have distress when connecting the LCD TV Panasonic TX-37LX75M to PC Laptop HP 520 or HP 540.

I used VGA D-sub port to connect. With others Laptop I’ve used before, it’s OK (Sony Vaio laptop, Shap Laptop): My LCD can show at the resolution 1280×768. But with the laptop HP 520 or HP 540, the LCD can’t dislay at that resolution but also show at 1024×768 and 800×600 only. When I set to 1280×768 or 1280×720 or higher, LCD TV screen was black like no signal, but laptop screen displays well.

I reckon there are some problem with output signal of this kind of Laptop (HP 520), may be it’s too weak. I’ve try to connect with CRT monitor, it was OK with all resolution.

Who had the same problem to me. Please show me your solution.

Thanks.