切换布局
显示结果
<html> <body> <script type = "text/javascript"> <!-- var book = "maths"; if( book == "history" ) { document.write("<b>History Book</b>"); } else if( book == "maths" ) { document.write("<b>Maths Book</b>"); } else if( book == "economics" ) { document.write("<b>Economics Book</b>"); } else { document.write("<b>Unknown Book</b>"); } //--> </script> </body> <html>
