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.