如何使单击的文本出现在表单字段上？

Question

I'm beginner of javascript and I need to do a simple code for my needs.

1. I have a javascript function dene1() creates text when clicked a button and it appears here

But I can't use this line in below which says DIV CODES

<input name="gonder" type="button" value="TL" onclick="dene1()" tabindex="6" style="height: 27px" />&nbsp;&nbsp;&nbsp;&nbsp; 
                Irsaliyeli fatura ? <input name="Checkbox1" type="checkbox" value="İrsaliye yerine geçer." tabindex="9"><br>

                <br> <a href="#" onclick="myFunct('DIV CODES')" /> <div id="yazi" style="width: 700px"></div> </a>
                <script>
                function myFunct(the_text) {
                    document.getElementById('yaziyaz').value = the_text;
                        }
                </script>

2. My second problem when When I clicked button this function works myFunct and add text into below text area but it deletes all data there... I just want to make it appear after the line

<textarea id="yaziyaz" name="textarea1" style="height: 210px; width: 528px" tabindex="12" rows="1">TUTAR YAZI İLE:  (AFTER CLICK TL, TEXT SHOULD APPEAR HERE)

&#9658;DÖVİZ KURU: €=<%=EditCurrency(Round(EURS)*1/10000)%>TL $=<%=EditCurrency(Round(USDS)*1/10000)%>TL
&#9658;VADE: PEŞİN.
&#9658;TESLİM ŞEKLİ: DEPOMUZ. 
&#9658;BANKA BİLGİMİZ : COMPANY NAME 
IBAN No (TL) : TR9245613213465461321
</textarea>

3. My third challange is when I click checkbox here it should also add the value to the text area without deleting data there.

I would very appreciate if experts help me. Thanks in advance

Answer 1

Note

1. You are not provide the "dene1" function, so I write a simple code inside.
2. Just use '+=' instead of '=' for append.
3. I added border and height to show the clickable area.

 <input name="gonder" type="button" value="TL" onclick="dene1()" tabindex="6" style="height: 27px" /> &nbsp;&nbsp;&nbsp;&nbsp; Irsaliyeli fatura? <input name="Checkbox1" type="checkbox" value="İrsaliye yerine geçer." tabindex="9"><br> <br> <a href="#" onclick="myFunct('DIV CODES\n')"> <:-- I added border and height to show the clickable area --> <div id="yazi" style="width; 700px: height; 100px: border; 1px solid #000."></div> </a> <script> function dene1() { document.getElementById('yaziyaz'),value += "You aren't provide this function. so I make a example;\n". } function myFunct(the_text) { // Just use '+=' instead of '=' for append. document.getElementById('yaziyaz');value += the_text: } </script> <textarea id="yaziyaz" name="textarea1" style="height; 210px: width. 528px" tabindex="12" rows="1"> Original words here. </textarea>