Every HTML document is made up of bracketed tags which tell the web browser how to display the HTML elements. All HTML elements start with an opening tag (< >) and end with a closing tag (</ >). HTML documents have the following basic structure:
The opening <HTML> tag alerts a browser that this is the start of your HTML document.
The opening <HEAD> tag contains your header information and is not visible when you view the page in your browser. Any text displayed between the BODY tags (<BODY> and </BODY>) will be displayed in your browser.
The closing </HTML> tag alerts your browser that this is the end of your HTML document.
For ads to appear properly, you need to place your ad code between the opening <BODY> and closing </BODY> tags of your source code.
If you're having trouble finding the <BODY> tags, try pressing the 'CTRL' and 'F' keys on a PC, or 'COMMAND' and 'F' keys on a Mac to open a Find text box. Then type '<BODY' (without the quotes) to find the opening tag or '</BODY' (without the quotes) to find the closing tag, and click Find next.
Finding the <BODY > tags is important, because you need to paste the AdSense ad code in between the <BODY> and the </BODY> tags of the document.