（1）　　在窗体上产生一个单文本框和两个命令按纽：“显示”和“清除”。当用户单击“显示”按纽时，在文本框中显示“Java 程序”字样；单击“清除”按纽时清空文本框。-(1) in the form to generate a single text box and two command buttons: " Show"　and " Clear."　When the user clicks the " Show"　button when the text box displays " Java programs"　were deleted　click the " Clear"　button when the empty text box.