function checkRegisterForm() { var n = document.getElementById('username'); var pwd = document.getElementById('password'); var pwd2 = document.getElementById('password-2'); var re1 = /^\w{3,10}$/; var re2 = /^.{6,20}$/; if(!re1.exec(n.value) ){ alert("用户名必须是3-10位英文字母或数字!"); }else if(!re2.exec(pwd.value)){ alert("口令必须是6-20位!"); }else if ( !pwd.value === pwd2.value){ alert("两次输入口令不一致！"); }else{ return true; } return false; }