用javascript实现简单的用户登录验证
<!DOCTYPE html> <html lang="en"> <head><meta charset="UTF-8"><title>Document</title> </head> <body><script type="text/javascript">function check() {if(document.getElementById("username").value=="") {alert("没有输入用户名！");return false;} else if(document.getElementById("password").value=="") {alert("没有输入密码！");return false;} else {alert("提交成功！")return true;}}</script><form name="form1"><input type="text" id="username"><input type="password" id="password" ><input type="submit" onclick="check()"></form> </body> </html>
更多参考：牛客网 https://www.nowcoder.com/questionTerminal/f904c482f21346a6a19efd5a82655518
