How to make text areas on web pages

how to make text areas on web pages.

maybe this is not strange to you that are familiar with html code and java scripts, but here the tutorial on here just for beginners like me
this is a sample :

Write the text or code you'd like to show here

The following code :
<form name="copy"><div align="center"><input value="Select All" onclick="javascript:this.form.txt.focus();this.form.txt.select();" type="button"/></div><p style="text-align: center;"><textarea style="padding: 3px; width: 300px; height: 50px;" name="txt">Write the text or code you'd like to show here</textarea></p></form>