Inputting a default image in case the src attribute of an html

Question

Is there any way to render a default image in an HTML tag, in case the src attribute is invalid (using only HTML)? If not, what would

Answer 1

For any image, just use this javascript code:

if (ptImage.naturalWidth == 0)
    ptImage.src = '../../../../icons/blank.png';

where ptImage is a tag address obtained by document.getElementById().