alert when the fields were null

Question

3.00/5 (2 votes)

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Hi friends,

I'm having values as name, age, sex and country.

I want to make alert box using javascript when these field were null.

my code is

title>Untitled Page</title>
<script type="text/javascript" language="javascript">
    function Checkid ()
    {
    var name=document.getElementById('TxtName');
    if(name=="")
    {
    alert("enter value in name field");
    }
    }
    </script>
</head>
<body>
    <form id="form1" runat="server">

    <div>
    <table>
    <tr>
    <td>
    Name
    </td>
    <td>
    <asp:TextBox ID="TxtName" runat="server"></asp:TextBox>
    </td>
    </tr>
    <tr>
    <td>
    Age
    </td>
    <td>
    <asp:TextBox ID="TxtAge" runat="server"></asp:TextBox>
    </td>
    </tr>
    <tr>
    <td>
    Sex
    </td>
    <td>
   <asp:RadioButtonList ID="RadioBtn" runat="server" RepeatDirection="Horizontal">
   <asp:ListItem>Male</asp:ListItem>
   <asp:ListItem>Female</asp:ListItem>
   </asp:RadioButtonList>
    </td>
    </tr>
    <tr>
    <td>
    Country
    </td>
    <td>
    <asp:DropDownList ID="Drp1" runat="server">
    <asp:ListItem>India</asp:ListItem>
    <asp:ListItem>USA</asp:ListItem>
    <asp:ListItem>UK</asp:ListItem>
    <asp:ListItem>France</asp:ListItem>
    <asp:ListItem>Japan</asp:ListItem>
    <asp:ListItem>Gremany</asp:ListItem>
    </asp:DropDownList>
    </td>
    </tr>
    <tr>
    <td colspan=2 align="center">
    <asp:Button OnClientClick="Checkid ();" ID="Btn1" Text="&nbsp;Save&nbsp;" runat="server" />
    </td>
    </tr>
    </table>

    </div>

I just want to learn java script, please suggest me the good pdf or any links with examples.

Thanks in advance

Posted 6-Jun-11 21:13pm

beginner in C#.net

Updated 6-Jun-11 21:48pm

v4

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Comments

Sergey Alexandrovich Kryukov 7-Jun-11 3:18am

PDF?!
--SA

thatraja 7-Jun-11 3:30am

I think he meant an e-book.

Sergey Alexandrovich Kryukov 7-Jun-11 16:18pm

Same thing is e-book -- ?!!!!
The idea of e-books is simply a crime against humanity, and a big fraud. Don't you think so?
--SA

thatraja 7-Jun-11 16:26pm

You mean illegal copies, right? Yeah I agree.
otherwise.... I think you are a hard copy books lover.

Sergey Alexandrovich Kryukov 7-Jun-11 17:14pm

Why illegal? Don't you realize that e-book is a legal crime itself. A book does not belongs the them, but they copy-protect it. You can pass your paper book to your children. Do you know that inheriting e-book a landing it to a friend is considered illegal? The whole thing is one big crime.
--SA

beginner in C#.net 7-Jun-11 3:46am

anythink i want to learn

Sergey Alexandrovich Kryukov 7-Jun-11 16:28pm

Web! HTML! Paper books.
Good luck in your learning!
Cheers,
--SA

anvas kuttan 7-Jun-11 3:49am

hey look my answer i tested it it working last solution ..

5 solutions

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Abhinav S · Answer 1 · 2011-06-06T21:18:00

Solution 1

Start with
http://www.tizag.com/javascriptT/javascriptalert.php[^]
http://www.w3schools.com/JS/js_popup.asp[^]

Posted 6-Jun-11 21:18pm

Abhinav S

Comments

beginner in C#.net 7-Jun-11 4:07am

tnx my 5

Toniyo Jackson · Answer 2 · 2011-06-06T21:18:00

Solution 2

I think these links will help you.

http://www.w3schools.com/js/default.asp[^]
http://www.learn-javascript-tutorial.com/[^]

More here[^]

And here your problem is, you are checking name which is object to null. It is not correct. You have to check the value like this.

C#

if(name.value == "")
{
  alert("enter value in name field");
}

Posted 6-Jun-11 21:18pm

Toniyo Jackson

Updated 6-Jun-11 21:24pm

v2

Comments

Dalek Dave 7-Jun-11 3:34am

Good Answer Toniyo.

Toniyo Jackson 7-Jun-11 3:35am

Thanks Dave :)

beginner in C#.net 7-Jun-11 4:07am

tnx my 5

Monjurul Habib · Answer 3 · 2011-06-06T21:23:00

Solution 3

http://forums.asp.net/t/1259399.aspx/1?javascript+to+check+textbox+is+empty[^]

Posted 6-Jun-11 21:23pm

Monjurul Habib

Deepthi Aravind · Answer 4 · 2011-06-06T21:32:00

Solution 4

Plase try this function

function check()
{
 var name=document.getElementById('<%=TextBox1.ClientID%>');
   if(name.value=="")
   {
   alert("enter value in name field");
   }
}

Refer this link.....
http://www.w3schools.com/js/default.asp[^]

Posted 6-Jun-11 21:32pm

Deepthi Aravind

Comments

Dalek Dave 7-Jun-11 3:34am

Good Call.

beginner in C#.net 7-Jun-11 4:07am

tnx my 5

anvas kuttan · Answer 5 · 2011-06-06T21:40:00

Solution 5

hi,

replace your script by this . i am tested its working fine

XML

<script type="text/javascript" language="javascript">
   function Checkid ()
   {
   var name=document.getElementById('TxtName').value;
   if(name=="")
   {
   alert("enter value in name field");
   }
   }
   </script>

Happy Coding

Posted 6-Jun-11 21:40pm

anvas kuttan

Comments

beginner in C#.net 7-Jun-11 3:52am

thanks..
i want alert for radiobutton too...

anvas kuttan 7-Jun-11 3:53am

is it work for you you for got to add .Value ok i will post for radio button too
accept it if you got the answer

beginner in C#.net 7-Jun-11 5:24am

i m waiting for ur radiobutton answer...

beginner in C#.net 7-Jun-11 4:08am

tnx my 5

Monjurul Habib 7-Jun-11 5:17am

thank you.