локатор, не найденный, когда сценарий Дистанционного управления селена, которым управляют?

Ниже форма моя веб-страница...

        <div class="padding">
            Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam nec arcu id enim tincidunt vulputate. Sed et elementum nisi. Donec rhoncus feugiat pharetra. Donec sed augue id urna congue commodo et quis nulla. 
            <form id="detailsForm" action="/xyz/home/personaldetails" method="post">
                  
                
                    Title:
                
                *
                

                
                    Please select
                    MrMrsMissDrMsSirProfDameLordLadyRHRevSisterFatherOther

                

                
            
              
                
                    First name:
                
                *
                

                <input id="firstName" name="firstName" type="text" value="Sivaji" maxlength="50"/>

                
            
                  
                
                    Last name:
                
                *
                

                <input id="lastName" name="lastName" type="text" value="Ganesan" maxlength="50"/>

                
            
When I copy the xpath from the above HTML, i am getting //*[@id="firstName"].

I am trying to use

selenium.type("//input[@id='firstName']", "Chandra"); or

selenium.type("//*[@id='firstName']", "Chandra");

I am getting

`12:28:37.854 INFO - Got result: ERROR: Element //input[@id='firstName'] not found on 

session 96a10231817c40e5aa370660fd05ba45`

Can any one please clarify that why it is not identifying? The same is,if I do recording in IDE, I can able to achieve,but in RC i could not.

Thanks Chandra