Javascript validation in CS file

///

    /// Apply Java Script Validation on Form
    ///

    private void ApplyValidation()
    {
        StringBuilder strClientScript = new StringBuilder();
        string strErrorMsg = string.Empty;

        strClientScript.Append(@" var frmvalidator  = new Validator
                    ('aspnetForm','" + btnSave.ClientID + "','','','" + lblErrorMessage.ClientID + "');");

        //Apply Validation on Content Title
        strErrorMsg = CommonFunction.GetErrorMessage("ERR1001")
            .Replace(AdminConstantKeys.TildeCharacter, "User Name");
        strClientScript.Append("frmvalidator.addValidation('"
            + txtUserName.ClientID + "','" + AdminConstantKeys.Required
            + "','" + strErrorMsg + "');");

        //Apply validation for User Name
        strErrorMsg = CommonFunction.GetErrorMessage("ERR1027")
            .Replace(AdminConstantKeys.TildeCharacter, "User Name");
        strClientScript.Append("frmvalidator.addValidation('" +
            txtUserName.ClientID + "','alphanumeric','" + strErrorMsg + "');");

        //Apply validation on Content Subject
        strErrorMsg = CommonFunction.GetErrorMessage("ERR1001")
            .Replace(AdminConstantKeys.TildeCharacter, "First Name");
        strClientScript.Append("frmvalidator.addValidation('" +
            txtFirstName.ClientID + "','" + AdminConstantKeys.Required +
            "','" + strErrorMsg + "');");

        strErrorMsg = CommonFunction.GetErrorMessage("ERR1001").
            Replace(AdminConstantKeys.TildeCharacter, "Last Name");
        strClientScript.Append("frmvalidator.addValidation('" +
            txtLastName.ClientID + "','" + AdminConstantKeys.Required +
            "','" + strErrorMsg + "');");

        strErrorMsg = CommonFunction.GetErrorMessage("ERR3901");
        strClientScript.Append("frmvalidator.addValidation('" +
            ddlUserType.ClientID + "','" + ddlUserType.Items[0].Text +
            "','" + strErrorMsg + "');");

        //Apply validation for Date difference between Exp and Publish date
        strErrorMsg = txtStopDate.ClientID + "|" +
            CommonFunction.GetErrorMessage("ERR4608");
        strClientScript.Append("frmvalidator.addValidation('" +
            txtStartDate.ClientID + "','dateDifference','"
            + strErrorMsg + "');");

        strErrorMsg = CommonFunction.GetErrorMessage("ERR1001")
            .Replace(AdminConstantKeys.TildeCharacter, AdminConstantKeys.EmailAddress);
        strClientScript.Append("frmvalidator.addValidation('"
            + txtEmail.ClientID + "','" + AdminConstantKeys.Required +
            "','" + strErrorMsg + "');");

        strErrorMsg = CommonFunction.GetErrorMessage("ERR1028").
            Replace(AdminConstantKeys.TildeCharacter, AdminConstantKeys.EmailAddress);
        strClientScript.Append("frmvalidator.addValidation('" +
            txtEmail.ClientID + "','email','" + strErrorMsg + "');");

        strErrorMsg = CommonFunction.GetErrorMessage("ERR1001").
            Replace(AdminConstantKeys.TildeCharacter, AdminConstantKeys.PhoneNumberMsg);
        strClientScript.Append("frmvalidator.addValidation('" +
            txtPhoneNumber.ClientID + "','" + AdminConstantKeys.Required +
            "','" + strErrorMsg + "');");


        strErrorMsg = CommonFunction.GetErrorMessage("ERR1028").Replace
            ("~~", AdminConstantKeys.PhoneNumber);
        strClientScript.Append("frmvalidator.addValidation('" +
            txtPhoneNumber.ClientID + "','" + AdminConstantKeys.PhoneNumberValidation +
            "','" + strErrorMsg + "');");

        strErrorMsg = CommonFunction.GetErrorMessage("ERR1001").
            Replace(AdminConstantKeys.TildeCharacter, AdminConstantKeys.CompanyNameMsg);
        strClientScript.Append("frmvalidator.addValidation('" +
            txtCompanyName.ClientID + "','" + AdminConstantKeys.Required +
            "','" + strErrorMsg + "');");

        strErrorMsg = "Please select at least one service";
        strClientScript.Append("frmvalidator.addValidation('" +
            lstAvailableServices.ClientID + "','" + AdminConstantKeys.ItemCount +
            "','" + strErrorMsg + "');");

        strErrorMsg = CommonFunction.GetErrorMessage("ERR1001").
            Replace(AdminConstantKeys.TildeCharacter, AdminConstantKeys.AdministrativeContactEmail);
        strClientScript.Append("frmvalidator.addValidation('" +
            txtAdmContactEmail.ClientID + "','" + AdminConstantKeys.Required +
            "','" + strErrorMsg + "');");

        strErrorMsg = CommonFunction.GetErrorMessage("ERR1028").
            Replace(AdminConstantKeys.TildeCharacter, AdminConstantKeys.AdministrativeContactEmail);
        strClientScript.Append("frmvalidator.addValidation('" +
            txtAdmContactEmail.ClientID + "','email','" +
            strErrorMsg + "');");

        strErrorMsg = CommonFunction.GetErrorMessage("ERR1001").
            Replace(AdminConstantKeys.TildeCharacter, AdminConstantKeys.TechnicalContactEmail);
        strClientScript.Append("frmvalidator.addValidation('" +
            txtTechContactEmail.ClientID + "','" + AdminConstantKeys.Required
            + "','" + strErrorMsg + "');");

        strErrorMsg = CommonFunction.GetErrorMessage("ERR1028").
            Replace(AdminConstantKeys.TildeCharacter, AdminConstantKeys.TechnicalContactEmail);
        strClientScript.Append("frmvalidator.addValidation('" +
            txtTechContactEmail.ClientID + "','" + AdminConstantKeys.EmailValidation + "','" +
            strErrorMsg + "');");


        strErrorMsg = CommonFunction.GetErrorMessage("ERR1001").
            Replace(AdminConstantKeys.TildeCharacter, AdminConstantKeys.StartDate);
        strClientScript.Append("frmvalidator.addValidation('" +
            txtStartDate.ClientID + "','" + AdminConstantKeys.Required +
            "','" + strErrorMsg + "');");


        strErrorMsg = CommonFunction.GetErrorMessage("ERR1006");
        strClientScript.Append("frmvalidator.addValidation('" +
            ddlStatus.ClientID + "','" + ddlStatus.Items[0].Text +
            "','" + strErrorMsg + "');");

        //Register the Client javascript
        if (!string.IsNullOrEmpty(strClientScript.ToString()))
        {
            ClientScript.RegisterStartupScript(this.GetType(),
                AdminConstantKeys.ValidationScript, strClientScript.ToString(), true);
        }
    }