javascript - How to fix "Uncaught TypeError: Cannot call method 'appendChild' of null" -

javascript - How to fix "Uncaught TypeError: Cannot call method 'appendChild' of null" -

i attempting grab text html text area, , phone call create() method when 'submit' button pressed. method trying utilize message text area, , post own p tag class, , post date stamp in own p tag, , own class.

these both in div 'comments'. error getting (using developer tools in chrome), is

uncaught typeerror: cannot phone call method 'appendchild' of null.

this aimed @ "cmt.appendchild(divtag);". new javascript, , practise me increment skills. help appreciated!

var cmt = document.getelementbyid('comments'); function create() { var username = 'user', message = document.getelementbyid("textbox").value, divtag = document.createelement('div'), p1 = document.createelement('p'), p2 = document.createelement('p'); divtag.classname = 'comment'; p1.classname = 'date'; p1.innerhtml = new date(); divtag.appendchild(p1); p2.classname = 'message'; p2.innerhtml = username + ': ' +message; divtag.appendchild(p2); cmt.appendchild(divtag); }

the error getting suggests there no element id "comments" on page. document.getelementbyid homecoming null when no element such id found, , cmd.appendchild(divtag) executed null.appendchild(divtag).

if element exists, may executing javascript assigns cmt variable before element created browser. prevent that, standard practice place <script> tag includes external javascript just before closing </body> tag.

if can't move script tag reason, seek running code assigns variable $(document).ready() (jquery) or equivalent.

javascript append appendchild