Question

The code below validate two nameserver textbox. As you can see there is redundancy in the javascript code. // validate textbox 1 and // validate textbox 2. Is there anyway I could just use one script.. you know I just want to use 1 validation function to validate two textbox. I’m sorry for my English I hope you all can understand me. Thank you.

    <script type="text/javascript">

// validate textbox 1
     function validate_domain(){
       var nameserver1 = document.getElementById('nameserver1').value;
       var domain_array = nameserver1.split('.');

      var domain = domain_array[0];
    //This is reguler expresion for domain validation
      var reg = /^([A-Za-z0-9])+[A-Za-z0-9-]+([A-Za-z0-9])$/;

    if(domain == ''){
         alert("Please enter the domain name"); 
         document.getElementsById('nameserver1').focus();
         return false; 
    } 

    if(reg.test(domain) == false){
       alert("Invalid character in domain. Only letters, numbers or hyphens are allowed.");
      document.getElementsById('nameserver1').focus();
       return false;
    }

    }



    // validate textbox 2
     function validate_domain(){
       var nameserver1 = document.getElementById('nameserver1').value;
       var domain_array = nameserver2.split('.');

      var domain = domain_array[0];
    //This is reguler expresion for domain validation
      var reg = /^([A-Za-z0-9])+[A-Za-z0-9-]+([A-Za-z0-9])$/;

    if(domain == ''){
         alert("Please enter the domain name"); 
         document.getElementsById('nameserver2').focus();
         return false; 
    } 

    if(reg.test(domain) == false){
       alert("Invalid character in domain. Only letters, numbers or hyphens are allowed.");
      document.getElementsById('nameserver2').focus();
       return false;
    }

    }
    </script>

 <fieldset class="inlineLabels">

            <label for="name">Nameserver 1</label>
            <input type="text" class="textInput" maxlength="255" size="30" value="" id="nameserver1" name="nameserver1">

            <label for="data">Nameserver 2</label>
            <input type="text" class="textInput" maxlength="255" size="30" value="" id="data" name="nameserver2">

        </fieldset>

          <button onclick="validate_domain(); submitForm('page1','directpage.php');" value="Validate" name="btn_validate" type="button" class="positive iconstxt icoPositive"><span>Save</span></button>

Answer 1

Well here is another approach:

function ValidateDomain(){
    function CheckForBlank(domain, textBox){
        if(domain == ''){
             alert("Please enter the domain name"); 
             document.getElementsById('nameserver1').focus();
             return false; 
        } 
    }
    function CheckForFormat(domain, textBox){
        if(reg.test(domain) == false){
            alert("Invalid character in domain. Only letters, numbers or hyphens are allowed.");
            document.getElementsById('nameserver1').focus();
            return false;
        }
    }
    function GetDomainName(inputId){
        var serverName = document.getElementById(inputId).value,
            domain_array = serverName.split('.');

        return domain_array[0];
    }
    var nameserver1 = GetDomainName('nameserver1'),
        nameserver2 = GetDomainName('nameserver2'),
        nameServerInput1 = document.getElementsById('nameserver1');
        nameServerInput2 = document.getElementsById('nameserver2');

    if (CheckForFormat(nameserver1,nameServerInput1) && CheckForBlank(nameserver1,nameServerInput1) 
        && CheckForFormat(nameserver2,nameServerInput2) && CheckForBlank(nameserver2,nameServerInput2)){
        //This means you are valid
        return {
            name1:nameserver1,
            name2:nameserver2 
        }
    }
    return false;
}