AnEroor while uploading Sketch

I have connected the ARDUINO MEGA2560 When connected the both LED's Blink continuously, and while uploading Shows message " An error while uploading sketch"

And show below msg

avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_getsync(): timeout communicating with programmer

Can anyone help?

Have you tried the instructions here.