JS validation - onsubmit

[rbutler]

Here's my inquiry: I have programmed this simple js validation for my form:

<script type="text/javascript">
function userinformation(){
var message="Please complete the following: \n\n";
var noerrors=message;

var dayselected=document.topform.day.selectedIndex;
if(document.topform.day.options[dayselected].value=="null"){
message+="Please select a day\n";
}

if(document.topform.daterequested.value==""){
message+="Please provide a requested tour date\n";
}

var numberattendinglist=document.topform.numberattending.selectedIndex;
if(document.topform.numberattending.options[numberattendinglist].value=="null"){
message+="Please select a day\n";
}

if(document.topform.firstname.value==""){
message+="Please provide your first name\n";
}

if(document.topform.lastname.value==""){
message+="Please provide your last name\n";
}

if(document.topform.address.value==""){
message+="Please provide your address\n";
}

if(document.topform.city.value==""){
message+="Please provide your city\n";
}

if(document.topform.state.value==""){
message+="Please provide your state\n";
}

if(document.topform.zip.value==""){
message+="Please provide your zip code\n";
}

if(document.topform.highschool.value==""){
message+="Please provide your high school\n";
}

if(document.topform.gradyear.value==""){
message+="Please provide your graduation year\n";
}

if(document.topform.phonenumber.value==""){
message+="Please provide your phone number\n";
}


if(message==noerrors){
        topform.submit();    
    }else{
        alert(message);
    return false;
    }
}

On my form tag, I have:

<form onsubmit="userinformation();return false">

However, my form will not submit, which with the return false statement on the onsubmit handler, it won't. However, in my validation check at the end of the function, I have used the submit method relating to my form to execute the form and it doesn't work. Is there something simple I'm missing?