Urgent Help needed into missing text field not allowing me to enter text again

I am using contact form 7, when the user submit form it validates required missing fileds and showing error “Please fill the required field.” into each text field that are mandatory but the fields are not allowing the user to enter the text again where the error message occurs.
I need to make the mandatory fields editable to put the data into missing fileds. The form is here http://bitly.com/1ktUYpa

An urgent help required to fix the issue.

Thank you

https://wordpress.org/plugins/contact-form-7/