I am stuck on how to make a span element become hidden again when the JavaScript validation succeeds. Currently onchange and onblur a red span appears showing an error if there is no text or if there are numbers in a name field. This does not disappear when the correct text is put in. I was just wondering how to make this message disappear when the correct text is put in? Code is below.

JavaScript:

function validateName() {

    var name = form.firstname.value; 

    if (form.firstname.value == ) { 

        document.getElementById(firstnameInvalid).style.visibility = visible;  

        return false;

    } if (/[0-9]/.test(name)) {

        document.getElementById(firstnameInvalid).style.visibility = visible;

        return false;  

    } 

    return true;

}

Form HTML:

<form name=form method=post action= userdetails.html onsubmit=return validate(this)>



<p>First Name:<input type=text name=firstname onblur=validateName() onchange=validateName() id=name>

    <span id=firstnameInvalid style=color:red; visibility:hidden> First Name is Invalid </span>

</p>