multipy

I have 2 days trying to resolve this error and not and could, if you could help me I would appreciate it public void isFalling(EntityPlayer entityplayer) { if(entityplayer.field_70181_x < -0.40000000000000002D) { entityplayer.field_70181_x = entityplayer.field_70181_x + 0.10000000000000001D; entityplayer.field_70143_R = 0.0F; } } He says that the field does not recognize .field_70181