[PHP] global variables or not??

[skitum]

Hi all,
Help me please. I need $vartwo1 have the same value that $varone1. Look:

function one(){
?>
 <input type="radio" name="checar" value="rd1">
 <input type="radio" name="checar" value="rd2">
 <input type="submit" name="button">
<?
}

function two(){
$vartwo1=$varone1;
$vartwo2=$vartwo2;
----- HTML code ---------
}

if(isset($button))
{
    if($checar == rd1)
    {
    $varone1="blabla";
    $varone2="bla";
    two();
    }
    elseif($checar == rd2)
    {
    $varone1="bleble";
    $varone2="ble";
    }
    else
    {
    otherfunction();
    }
}

Should i use global variables? How should i use it?

Thanks in advance.

Peace & Love
skitum