■スクリプト
<HTML> <HEAD> <TITLE>prototype</TITLE> </HEAD> <BODY bgColor="white"> <CENTER> <H1>プロパティの追加</H1> </CENTER> <SCRIPT Language="JavaScript"> <!-- Image.prototype.defW = 1024; theImage = new Image(); document.write(theImage.defW); // --> </SCRIPT> </BODY> </HTML>