验证数据正确后提交表单

<script>

function checkInformation(){
if(document.addressform.username.value=='')
{
alert('请输入收货人');
return false;
}
if(document.addressform.userphone.value=='')
{
alert('请输入手机号');
return false;
}
if(document.addressform.userintro.value=='')
{
alert('请输入地址');
return false;
}
document.addressform.submit();
}
</script>