Return Message If First Value Is Correct?

I'm trying to figure out how to make this work and I'm stumped. I wrote this code:

<script type=text/javascript>
function firstfunction();
{
if(document.form1.inputnumbers.value="55");
{
document.form1.outputstate.value="this is a number";
}
[Code]..

I'm trying to doing something really simple but I can't seem to make it work. I'm trying have the textarea display a certain message depending on if the first input box says a certain word or number. So like in the code, if the user types "55" or "never" in the first box, then the second box should say a certain message. Then I used the else statement so that if "55" or "never" is not entered, then the second box says nothing. If you can spot my error or suggest a different way of going about writing the code