Before you do that the ReplaceCodeTags function is already contained in inc_func_common.asp in v3.4.x. Instead of what Cripto9t posted; try the following:
Around line 1278 find the following:CodeTags(1,1,2) = "<pre id=""code""><font face=""courier"" size=""" & strDefaultFontSize & """ id=""code"">"
CodeTags(1,2,2) = "</font id=""code""></pre id=""code"">"
Comment out those two lines (by adding a ' before them) and add the following two lines below them:CodeTags(1,1,2) = <form name=""it""><font face=""courier"" color=""" & strDefaultFontColor & """ size=""" & strDefaultFontSize & ""><textarea name=""getcode"" cols=""60"" rows=""4"" readonly=""readonly"">"
CodeTags(1,2,2) = "</textarea id=""code""></font><br /><button onclick=""this.form.getcode.focus();this.form.getcode.select();var ttr=this.form.getcode.createTextRange();ttr.execCommand('copy');"">copy code</button></form>"