<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>定時器setTimeout</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta name="description" content="布爾教育 http://www.itbool.com" /> <script> function bang(){ document.getElementsByTagName('img')[0].src="off.png"; } //注意這裏有引號 setTimeout('bang()',3000); </script> </head> <body> <h1>定時器,三秒以後圖片更換</h1> <img src="on.png" alt="" /> </body> </html> /*****************************************/ <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>定時器setTimeout</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta name="description" content="布爾教育 http://www.itbool.com" /> <script> function bang(){ var inp=document.getElementsByName('on')[0]; var time=inp.value-1; inp.value=time; if(time==0){ document.getElementsByTagName('img')[0].src="off.png"; //clear定時器 clearInterval(clock); } } //注意這裏有引號 var clock=setInterval('bang()',1000); </script> </head> <body> <h1>定時器,以及清除定時器</h1> <input type="button" value="5" name="on"/> <img src="on.png" alt="" /> </body> </html>