Switch Debug Console to ON as shown in Figure 11-2.
Figure 11-2 Enabling the Debug Console
When the Debug Console is on, a banner appears above your webpage if there are messages in the console, as shown in Figure 11-3. Click the banner to view the messages.
The console displays the messages in the order in which they occur, as shown in Figure 11-4. Each message description contains the type of message, the line number and filename of the document, and the text message. The types of messages are log, info, warning, and error. Click the Clear button to remove all messages from the console.
Tips appear in the console if you don’t follow certain guidelines. For example, if you set the viewport width to 320 instead of using the device-width constant, then an HTML tip appears in the console as shown in Figure 11-6. A similar tip appears if you set the viewport height to 480 instead of using the device-height constant.
For example, the following HTML fragment generates the first three HTML messages in the console shown on the left side in Figure 11-5. Syntax errors also generate messages.
<meta name = "viewport" content = "width = 320, height = 480, m = no">