■スクリプト
<HTML> <HEAD> <TITLE>Sample</TITLE> </HEAD> <BODY bgColor="white"> <CENTER> <H1>指定位置の文字を抜き出します</H1> </CENTER> <TABLE BORDER="1"> <SCRIPT Language="JavaScript"> <!-- str = "Dreamcast"; for (i=0; i<str.length; i++) alert(i,":",str.substring(0,i)); // --> </SCRIPT> </TABLE> </BODY></HTML>