ASP.Net: Text Box Validation - Part II

ASP.Net: Text Box Validation Part I

Introduction

In this article I explain some more validations of Text box control in ASP.Net.

Requirement

Add the following line in the head section to create a function for validation.

<script language="javascript" type="text/javascript">

Then create a function:

function validate()

{
. //function body
.
.
return true;
}

Solution

1. Text box cannot be blank :
   
   This kind of validation does not allow blank text box controls in ASP.Net. Add the following function body:

   if (document.getElementById("<%=txtName.ClientID%>").value=="")

   {
        alert("Name Feild can not be blank");
        document.getElementById("<%=txtName.ClientID%>").focus();
        returnfalse;
   }

   Where txtName is the Id of a Text Box control.
    

2. Email id Validation
   
   This kind of validation accepts only email id syntax in a text box control in ASP.Net. Add the following function body:

   if(document.getElementById("<%=txtEmail.ClientID %>").value=="")

   {

   alert("Email id can not be blank");

   document.getElementById("<%=txtEmail.ClientID %>").focus();

   returnfalse;

   }

   var emailPat = /^(\".*\"|[A-Za-z]\w*)@(\[\d{1,3}(\.\d{1,3}){3}]|[A-Za-z]\w*(\.[A-Za-z]\w*)+)$/;

   var emailid=document.getElementById("<%=txtEmail.ClientID %>").value;

   var matchArray = emailid.match(emailPat);

   if (matchArray == null)

   {

   alert("Your email address seems incorrect. Please try again.");

   document.getElementById("<%=txtEmail.ClientID %>").focus();

   returnfalse;

   }
   
   Where txtEmail is the Id of a Text Box.

    

3. Web URL

   This kind of validation only accepts a web URL in a Text box control. Add the following function body:

   if(document.getElementById("<%=txtWebURL.ClientID %>").value=="")

   {

               alert("Web URL can not be blank");

               document.getElementById("<%=txtWebURL.ClientID %>").value="http://"

               document.getElementById("<%=txtWebURL.ClientID %>").focus();

               returnfalse;

    }

    var Url="^[A-Za-z]+://[A-Za-z0-9-_]+\\.[A-Za-z0-9-_%&\?\/.=]+$"

    var tempURL=document.getElementById("<%=txtWebURL.ClientID%>").value;

    var matchURL=tempURL.match(Url);

     if(matchURL==null)

     {

             alert("Web URL does not look valid");

             document.getElementById("<%=txtWebURL.ClientID %>").focus();

             returnfalse;

     } 

   Where txtWebURL is the Id of a Text Box.
    

4. ZIP Format

   This kind of validation only accepts a ZIP format of data in the Text Box control in ASP.Net. Add the following function body:

   if (document.getElementById("<%=txtZIP.ClientID%>").value=="")

   {

   alert("Zip Code is not valid");

   document.getElementById("<%=txtZIP.ClientID%>").focus();

   returnfalse;

   }

   var digits="0123456789";

   var temp;

   for (var i=0;i<document.getElementById("<%=txtZIP.ClientID %>").value.length;i++)

   {

   temp=document.getElementById("<%=txtZIP.ClientID%>").value.substring(i,i+1);

   if (digits.indexOf(temp)==-1)

   {

   alert("Please enter correct zip code");

   document.getElementById("<%=txtZIP.ClientID%>").focus();

   returnfalse;

   }

   } 

   Where txtZIP is the Id of a text box.

   When you done with all call the function validate on the Button on which you want output as in the following :

      <asp:Button ID="btnSubmit" OnClientClick=" return validate()" runat="server" Text="Submit" />

Now save the entire work and view the page in a browser. It will work perfectly.