I use the W3c HTML Validator add-on for Fire Fox. Once installed,
You visit your site or page and then from the FF ToolBar, select Tools > Web Developer > Page Source
The source file opens in the top pane while the validation errors in the bottom pane.
I then click “Type” in the validation errors (bottom) pane to sort the errors by type.
You can click on an error and its highlighted in the top pane (source).
Errors like ‘entity’ can be ingnored but I do use it to to find open tags and missing attributes like ALT for example.
for example – heaven4casinos
first error is at line 16 (that should be type= and not tyle=)
[PHP]
[/PHP]