ช่วยด้วยค่ะ เกี่ยวกับการนำ javascript มาจากเว็บมาใช้ในงาน

<script type='text/javascript'> 
function insert(el,ins) { 
if (el.setSelectionRange){ 
el.value =el.value.substring(0,el.selectionStart) + ins +'\n'+ el.value.substring(el.selectionStart,el.selectionEnd) + el.value.substring(el.selectionEnd,el.value.length); 
} 
else if (document.selection && document.selection.createRange) { 
el.focus(); 
var range = document.selection.createRange(); 
range.text =ins + range.text; 
} 
}
</script> 
 
<form> 
<input type='text' name='txt1' id='txt1'>
<input type='button' value='my freind' onclick='insert(this.form.ta,txt1.value)' > 
<br /> 
<textarea rows='7' cols='30' name='ta'>
</textarea> 
</form>

แต่นำมาใช้จริงรันไม่ได้ค่ะ หนูทำผิดตรงไหนบ้างอ่ะค่ะช่วยด้วยค่ะ

function manage_Broadc(){
	$content=faceMain_up();		
	$content .="<!--BODY -->
			<div class=\"Boxbody\">
			<div class=\"Boxbody\" id=\"Boxbody-head\">&nbsp; ";
				if($_REQUEST['menu'] == ''){
					$content.="Welcome To ";
				}else{
					$content.=$_REQUEST['menu'];
				}
	 $content .="</div><br><br><br>";//head body
	//start
	 $content .="<script type='text/javascript'> 
function insert(el,ins) { 
if (el.setSelectionRange){ 
el.value =el.value.substring(0,el.selectionStart) + ins +'\n'+ el.value.substring(el.selectionStart,el.selectionEnd) + el.value.substring(el.selectionEnd,el.value.length); 
} 
else if (document.selection && document.selection.createRange) { 
el.focus(); 
var range = document.selection.createRange(); 
range.text =ins + range.text; 
} 
}
</script>";
$content .="<form> 
<input type='text' name='txt1' id='txt1'>
<input type='button' value='my freind' onclick='insert(this.form.ta,txt1.value)' > 
<br /> 
<textarea rows='7' cols='30' name='ta'>
</textarea> 
</form>";	
 $content.="</div>"; // end div body
$content.=faceMain_down();
return $content;
}