Sys.Debug trace Method
Appends a text line to the debugger console and to the trace console, if available.
You can create a trace console on a Web page by adding a textarea element and setting its id attribute set to "Trace Console".
Debugging behavior, requirements, and the output of trace messages vary with different browsers. For more information, see Debugging and Tracing Ajax Applications Overview
The following example shows a click handler function that writes a line to the trace console. The example assumes the existence of an HTML element named Text1 in the default form element of the page. This is part of a larger example from the Sys.Debug class overview.