function Check()
        {
            var flag = true;
            var username = document.getElementById("txtusername").value;
            var pass = document.getElementById("txtpassword").value;

            if (username == "")
            {

                document.getElementById("checkusername").style.display = "inline";
                flag = false;

            }
            else
            {
                document.getElementById("checkusername").style.display = "none";
            }

            if (pass == "")
            {
                document.getElementById("checkPassword").style.display = "inline";
                flag = false;
            }
            else
            {
                document.getElementById("checkPassword").style.display = "none";
            }
            return (flag);
        }
    </script>
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
  <center>
        <h1>התחברות </h1>
     <table border="1" width="40%">
        <tr>
             <td>  שם משתמש</td>
             <td><input type="text" name="txtusername" id="txtusername" /> </td>
             <td><label for="checkusername" id="checkusername" name="checkusername" style="color:red; font-size:x-large;display:none;">*</label>  </td>
         </tr>
         <tr>
             <td> סיסמה</td>
             <td><input type="password" id="txtpassword" name="txtpassword"  /></td>
             <td> <label for="checkPassword" id="checkPassword" name="checkPassword" style="color:red;display:none;">*</label> </td>
         </tr>
          <tr>
             <td> </td>
             <td><input type="submit" name="btnlogin" id="btnlogin" value="התחבר" /></td>
             <td>  </td>
              </tr>
          <td> </td>
             <td><input type="reset" name="btnreset" id="btnreset" value="נקה" /> </td>
             <td>  </td>
              <tr>
         </tr>
        </table>
         </center>
</asp:Content>