Mega Code Archive
Controlling Script Errors
<![CDATA[
/*
JavaScript Bible, Fourth Edition
by Danny Goodman
John Wiley & Sons CopyRight 2001
*/
<HTML>
<TITLE>Error Dialog Control</TITLE>
<SCRIPT LANGUAGE="JavaScript1.1">
// function with invalid variable value
function goWrong() {
var x = fred
}
// turn off error dialogs
function errOff() {
window.onerror = doNothing
}
// turn on error dialogs with hard reload
function errOn() {
window.onerror = handleError
}
// assign default error handler
window.onerror = handleError
// error handler when errors are turned off...prevents error dialog
function doNothing() {return true}
function handleError(msg, URL, lineNum) {
var errWind = window.open("","errors","HEIGHT=270,WIDTH=400")
var wintxt = "<HTML><BODY BGCOLOR=RED>"
wintxt += "<B>An error has occurred on this page. "
wintxt += "Please report it to Tech Support.</B>"
wintxt += "<FORM METHOD=POST ENCTYPE='text/plain' "
wintxt += "ACTION=mailTo:support4@dannyg.com >"
wintxt += "<TEXTAREA NAME='errMsg' COLS=45 ROWS=8 WRAP=VIRTUAL>"
wintxt += "Error: " + msg + "\n"
wintxt += "URL: " + URL + "\n"
wintxt += "Line: " + lineNum + "\n"
wintxt += "Client: " + navigator.userAgent + "\n"
wintxt += "-----------------------------------------\n"
wintxt += "Please describe what you were doing when the error occurred:"
wintxt += "</TEXTAREA><P>"
wintxt += "<INPUT TYPE=SUBMIT VALUE='Send Error Report'>"
wintxt += "<INPUT TYPE=button VALUE='Close' onClick='self.close()'>"
wintxt += "</FORM></BODY></HTML>"
errWind.document.write(wintxt)
errWind.document.close()
return true
}
</SCRIPT>
</HEAD>
<BODY>
<FORM NAME="myform">
<INPUT TYPE="button" VALUE="Cause an Error" onClick="goWrong()"><P>
<INPUT TYPE="button" VALUE="Turn Off Error Dialogs" onClick="errOff()">
<INPUT TYPE="button" VALUE="Turn On Error Dialogs" onClick="errOn()">
</FORM>
</BODY>
</HTML>
]]>