crystal panel 30 and the frame 20 together comprises the following steps applying a force to the clasp 231 of the sidewall 23 to make the clasp 231 of the sidewall 23 bend outwardly putting the liquid crystal panel 30 on the base portion 25 and pushing one side of the liquid crystal panel 30 against the clasp 231 of the sidewall 24 and positioning another side of the liquid crystal panel 30 so that it abuts against one of the two arc parts 221 pressing down the liquid crystal panel 30 so that it is received in the receiving space and removing the pressing force whereby the two clasps 231 resiliently rebound inwardly thus the clasps 231 the two arc parts 221 of the frame 20 and the first sidewall 21 cooperate to hold the liquid crystal panel 30 in the frame 20 an assembly of the liquid crystal panel 30 and the frame 20 is shown in fig5 and 7 the liquid crystal panel 30 is accommodated in the frame 20 the clasps 231 of the frame 20 hold two opposite sides of the liquid crystal panel 30 whereby the clasps 231 provide horizontal elastic forces to prevent the liquid crystal panel 30 from moving in horizontal directions in addition the first protrusions 234 of the clasps 231 cooperate with the base portion 25 to prevent movement of the liquid crystal panel 30 in vertical directions furthermore the arc parts 221 prevent the liquid crystal panel 25 from moving in horizontal directions when the liquid crystal panel 30 is taken out of the frame 20.