7" TFT w/ RA8875

hiiiii,,,
i start work on er-tftm070-5 tft module with arduino mega. i have faces some problem on the time of compilation the problem is..

error: 'class RA8875' has no member named 'fillScreen'
'class RA8875' has no member named 'changeMode'
'TEXT' was not declared in this scope

please give solution.