JSFiddle - React, Tailwind, and code Playground

HTML

<form name="login" onsubmit="return check(this)">
    &nbsp<input type="text" placeholder="Enter the Username" name="user"/> <br />
      <input type="password" placeholder="Enter the Password" name="pwd"/><br/><br/>
      <input type="checkbox" name="en" value="en" />Remember Me<br>
      <input type="submit" value="Login"/>
      <input type="reset" value="Cancel"/>
    </form>

JavaScript

function check(frm)
    {
       if(frm.user.value == "user" && frm.pwd.value == "pwd")
       {
           window.open('inbox.html','_self')
       }
       else
       {
           alert("Error Password or Username")
       }
    
       return false;
    }