foucs() ではありません
var form1 = document.form1;
var str = form1.user.value;
if(objExp.test(str) == true){
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head> <script language="javascript"> function method1(){ var i = 1; var j = 1; for(i = 1; i <= 9; i++){ for(j = 1; j <= i; j++){ document.write(i + "*" + j + '=' + i * j + " "); } document.write('<br>'); } } function fun(){ alert('你好!!'); } function jianche(){ /* 此函数的调用出现问题 */ var form1 = document.form1; var str = form1.user.value; if(str == ""){ alert("请输入真实姓名!"); form1.user.focus(); } else { var objExp = /[\u4E00-\u9FA5]{2,}/; if(objExp.test(str) == true){ alert("输入了正确的名字!"); } else { alert("输入的名字不正确!"); } } } </script> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"/> <title>方法调用</title> <style type="text/css"> <!-- .STYLE1{ font-size:xx-large } --> </style></head><body><form id="form1" name="form1" method="post" action=""> <p align="center" class="STYLE1">登录系统</p> <p align="center">用户名: <input type="text" name="user"/></p> <p align="center">密码; <input type="password" name="password"/> </p> <div align="center"> <input type="submit" name="Submit" value="提交"/> <input type="reset" name="Submit2" value="重置"/> <input type="button" name="Submit3" onclick="method1()" value="检测"/> <input type="button" name="Submit4" onclick="fun()" value="好"/> <input type="button" name="Submit5" onclick="jianche()" value="很好"/> /*点击按钮“很好”时,没有反应*/ </div></form></body></html>