Javascript language

<script language="javascript"
 type="text/javascript">
function validate()
{
if (document
.getElementById(
"<%=TextBox1.ClientID%>").value==""
)
{
alert("Name can not be blank"
);
document.getElementById
("<%=TextBox1.ClientID%>").focus();
return false;
}

if(document
	  .getElementById("<%=TextBox2.ClientID %>").
	  value=="")
{
  alert(
 "Email id can not be blank");
  document.getElementById
(
"<%=TextBox2.ClientID %>"
)
.focus();
return false;
 }
 var emailPat= /^([A-Za-z0-9_\-\.])+\@
	 ([A-Za-z0-9_\-\.])+\.([A-Za-z]
 {2,
 4
})$/;
 var emailid=
document.getElementById(
"<%=TextBox2.ClientID %>").value;
 var matchArray = emailid.match(emailPat);
  if 
 (matchArray == null)
   {
  alert();
 document.getElementById(
 "<%=TextBox2.ClientID %>").focus();
   return false;
    }
    if (document
	.getElementById
	("<%=TextBox3.ClientID%>")
	.value==
	"")
{
alert(
"Contact Number can not be blank");
document.getElementById(
"<%=TextBox3.ClientID%>").focus();
return false;
}
var digits=
	 "0123456789";
var temp;
for (
	 var i=0;i<
	 
	 document.getElementById(
"<%=TextBox3.ClientID %>").value.length;i++)
{
temp=document.
getElementById("<%=TextBox3.ClientID%>").
value.substring(i,i+1);
if (digits.indexOf(temp)==-
	 1)
{
alert("Please enter correct Contact Number"
	  );
document.getElementById(
	  "<%=TextBox3.ClientID%>").focus();
return false;
}
}
if(document
	  .getElementById(
	  "<%=TextBox5.ClientID %>").value==
	  "")
    {
alert("City can not be blank");
document.getElementById(
	 "<%=TextBox5.ClientID %>").value;
document.getElementById(
	  "<%=TextBox5.ClientID %>").focus();
return false;
    }
if(
	  document.getElementById(
	  "<%=TextBox6.ClientID %>").value==
	  "")
    {
alert("Password can not be blank");
document.getElementById(
	 "<%=TextBox6.ClientID %>").value;
document.getElementById(
	 "<%=TextBox6.ClientID %>").focus();
return false;
    }
    if(document
	.getElementById("<%=TextBox7.ClientID %>")
	.value=="")
    {
alert("Please Re-Enter Password ");
   document.getElementById(
   "<%=TextBox7.ClientID %>").value;
   document.getElementById(
   "<%=TextBox7.ClientID %>").focus();
    return false;
    }
return true;
}
</script>

Default.aspx Code

<%@ Page Language="C#"
 AutoEventWireup="true"  
Codevirtual="Default.aspx.cs"
 Inherits="_Default" 
 %>
<!DOCTYPE html PUBLIC 
"-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"
>
<html xmlns="http://www.w3.org/1999/xhtml"
>
<head runat="server"
>
    <title>Form 
	Validation</title>
    </head>
<body>
    <form id="form1" 
	
	runat="server">
    <script language="javascript"
	>

//Write JavaScript Code
</script>
  <div>
  <table >
  <tr><td>Name</td>
  <td><asp:TextBox ID="TextBox1"
   runat="server"
             Width="193px"
	 
			 ></asp:TextBox></td></tr>
            <tr> <td>Email ID</td>
     <td><asp:TextBox ID=
		  "TextBox2"
 runat="server"
 Width="193px" 
    ToolTip="Enter unique Email ID"
 AutoPostBack=
	 "True">
      </asp:TextBox></td></tr>
      <tr><td>Contact Number</td><td>
      <asp:TextBox ID="TextBox3"
	runat="server"
Width="193px" 
  AutoPostBack="True"
  ></asp:TextBox></td></tr>
            <tr><td> Sex</td>
    <td><asp:RadioButton ID="RadioButton1" 
	runat="server" 
	Text="Male" 
	GroupName="a" />
    <asp:RadioButton ID="RadioButton2" 
	runat="server"
	 Text=
	 "Female" GroupName="a"
	  /></td>
      </tr>
  <tr> <td>Enter&nbsp; City</td>
   <td><asp:TextBox ID="TextBox5"
    runat="server"
	 Height="22px"
	  Width=
	  "193px"
	  ></asp:TextBox>
                </td></tr>
  <tr><td>
  Password</td>
    <td><asp:TextBox ID=
	"TextBox6" 
	runat="server"
	 Width="193px"
	 TextMode="Password"
	  >
    </asp:TextBox></td>            </tr>
    <tr><td>Re-Enter Password
	</td>
     <td> <asp:TextBox ID="TextBox7"
	  runat="server"
	   TextMode="Password"
	  Width="193px" 
              Height="22px"
			  ></asp:TextBox> </td> </tr>
      <tr><td><asp:Button
ID="Button1"
	  runat="server"
		Text="Submit" 
                   onclick="Button1_Click" 
						
	OnClientClick="return validate()
	 " />
     </td></tr></table></div>
    </form>
</body>
</html>