lol....when the current price is below the line, the line is known as resist. when current price is above that line, that line is now known as support (even tho all along it's the same line)

as a general guide, enter at or near support, and exit at or near resist

for dual moving averages, it is an EXTREMELY rough guide. Use it only as a confirmation, ie base your preliminary research/analysis on other indicators. For dual MA, buy signals occur when the shorter MA crosses over the longer MA, ie when 20 MA crosses over 50 MA