将用户从键盘输入的十进制数（不超过65535）转换成为十六进制数并显示。如果输入不是0～9的数字，则显示错误提示。-The user from the keyboard input of a decimal number (not more than 65,535) and transform it into hexadecimal number and displayed. If the input is not 0 ~ 9 figures, it shows error message.