时间: 2021-07-31 作者:daque
运用一个前提语句实行,这个表单如次:<form name="register" method="post" action onsubmit="return check();"><p align="center"> email:<input type="text" name="email" size="20"> <input type="submit" value="提交" name="b1"> <input type="reset" value="重填" name="b2"></p></form> 当存户端提交时触发onsubmit事变挪用查看因变量举行确定,这个因变量如次:function check(){ if(document.register.email.value.length!=0) { if (document.register.email.value.charat(0)=="." document.register.email.value.charat(0)=="@" document.register.email.value.indexof('@', 0) == -1 document.register.email.value.indexof('.', 0) == -1 document.register.email.value.lastindexof("@") ==document.register.email.value.length-1 document.register.email.value.lastindexof(".") ==document.register.email.value.length-1) { alert("email的方法不正確!"); document.register.email.focus(); return false; } } else { alert("email的不许为空!"); document.register.email.focus(); return false; } return false;}