vložení do textu podle ikonky

<img onclick="pridatBold()" src="Bold.gif"></img><img onclick="pridatItalic()" src="Italic.gif"</img> <img onclick="pridatUnderline()" src="Underline.gif"> 

<form name="formular">
<textarea name="edit"></textarea>

</form>

<script type="text/javascript">
//vytvořeno podle skriptů uživatelů měsíček a Chamurappi na diskusi měl by tenhle skript fungovat (mě nefunguje) ? 
function pridatBold() {
document.formular.edit.value += '<b></b>';
}
function pridatItalic() {
document.formular.edit.value += '<i></i>';
}

function pridatUnderline() {
document.formular.edit.value += '<u></u>';
}

</script> 

<button oncclick="document.write(document.formular.edit.value)">odeslat</button> přepíše to celou stránku, což je špatně chtěl jsem to udělat innerHTML a divem ale to furt vyhazovalo "undefined" --> 

$vystup = Str_iReplace("[.b]","<strong>",$vystup); //tucne
$vystup = Str_iReplace("[./b]","</strong>",$vystup); //tucne konec
$vystup = Str_iReplace("[.i]","<em>",$vystup); //kurziva
$vystup = Str_iReplace("[./i]","</em>",$vystup); //kurziva konec
$vystup = Str_iReplace("[u]","<u>",$vystup); //podtrzeni
$vystup = Str_iReplace("[/u]","</u>",$vystup); //podtrzeni konec
$vystup = Str_iReplace("[quote]","„",$vystup); //citace
$vystup = Str_iReplace("[/quote]","˝",$vystup); //citace konec
$vystup = nl2br($vystup);  //odradkovani

if (!count($BBmeda)) {
                
                $BBmeda['url']  = '<a href="{URL}" rel="nofollow" target="_blank" title="{DESCRIPTION} - {URL}">{DESCRIPTION}</a>';
                $BBmeda['email']= '<a href="mailto:{EMAIL}">{EMAIL}</a>';

                $BBmeda['url1'] = str_replace('{URL}', '\\1\\2', $BBmeda['url']);
                $BBmeda['url1'] = str_replace('{DESCRIPTION}', '\\1\\2', $BBmeda['url1']);

                $BBmeda['url2'] = str_replace('{URL}', 'http://\\1', $BBmeda['url']);
                $BBmeda['url2'] = str_replace('{DESCRIPTION}', '\\1', $BBmeda['url2']);

                $BBmeda['url3'] = str_replace('{URL}', '\\1\\2', $BBmeda['url']);
                $BBmeda['url3'] = str_replace('{DESCRIPTION}', '\\3', $BBmeda['url3']);

                $BBmeda['url4'] = str_replace('{URL}', 'http://\\1', $BBmeda['url']);
                $BBmeda['url4'] = str_replace('{DESCRIPTION}', '\\2', $BBmeda['url4']);

                $BBmeda['email'] = str_replace('{EMAIL}', '\\1', $BBmeda['email']);

                // [url]xxxx://www.domena.tld[/url] 
                $BB_vstup[1] = "#\[url\]([a-z]+?://){1}([a-z0-9\-\.,\?!%\*_\#:;~\\&$@\/=\+\(\)]+)\[/url\]#si";
                $BB_nahrada[1] = $BBmeda['url1'];

                // [url]www.domena.tld[/url] (bez xxxx:// pouze www).
                $BB_vstup[2] = "#\[url\]([a-z0-9\-\.,\?!%\*_\#:;~\\&$@\/=\+\(\)]+)\[/url\]#si";
                $BB_nahrada[2] = $BBmeda['url2'];

                // [url=xxxx://www.domena.tld]odkaz[/url] 
                $BB_vstup[3] = "#\[url=([a-z]+?://){1}([a-z0-9\-\.,\?!%\*_\#:;~\\&$@\/=\+\(\)]+)\](.*?)\[/url\]#si";
                $BB_nahrada[3] = $BBmeda['url3'];

                // [url=www.domena.tld]odkaz[/url] (bez xxxx:// pouze www).
                $BB_vstup[4] = "#\[url=([a-z0-9\-\.,\?!%\*_\#:;~\\&$@\/=\+\(\)]+)\](.*?)\[/url\]#si";
                $BB_nahrada[4] = $BBmeda['url4'];

                // [email]user@domain.tld[/email] 
                $BB_vstup[5] = "#\[email\]([a-z0-9\-_.]+?@[\w\-]+\.([\w\-\.]+\.)?[\w]+)\[/email\]#si";
                $BB_nahrada[5] = $BBmeda['email'];

                // [img]xxxx://www.domena.tld[/img] 
                $BBmeda['img']  = '<img src="pre_o.php?obrazek={URL}" alt="obrazek-mimo-stranky" />';
                $BBmeda['img']  = str_replace('{URL}', '\\1\\2', $BBmeda['img']);

                $BB_vstup[6] = "#\[img\]([a-z]+?://){1}([a-z0-9\-\.,\?!%\*_\#:;~\\&$@\/=\+\(\)]+)\[/img\]#si";
                $BB_nahrada[6] = $BBmeda['img'];

        }

        $vystup = preg_replace($BB_vstup, $BB_nahrada, $vystup);
        
//DEFINICE SMAJLIKU

$vystup = Str_iReplace(":)","<img src=\"".$slozka_smajlici."/smich.gif\" alt=\":)\" align=\"absmiddle\" />",$vystup); //smajlik
$vystup = Str_iReplace(":-)","<img src=\"".$slozka_smajlici."/smich.gif\" alt=\":)\" align=\"absmiddle\" />",$vystup); //smajlik
$vystup = Str_iReplace(":D","<img src=\"".$slozka_smajlici."/lol.gif\" alt=\":-D\" align=\"absmiddle\" />",$vystup); //smajlik
$vystup = Str_iReplace(":-D","<img src=\"".$slozka_smajlici."/lol.gif\" alt=\":)\" align=\"absmiddle\" />",$vystup); //smajlik