Below is a function I am using to open "PDF" files from a folder and I want to pop up an alert window if the file does not exist, or if the new window is redirected to my server's error page. I have tried many different ideas but can't get anything to work. Can you help?!
<html>
<head>
<title>QuickSheet 1.0</title>
<script language="JavaScript">
function formHandler(datasheet){
var Spec = datasheet.modelnum.value.toUpperCase();
window.open("MYWEBSITEURL"+Spec+".pdf", "dataWindow", "status=yes,menubar=yes,location=yes,toolbar=no,scrollbars=yes"
;
}
</script>
</head>
<body bgcolor="#666666" text="#FFFFFF" link="#EEEEEE" vlink="#CCCCCC" alink="#CC0033">
<center>
<form name="datasheet">
<input type="text" name="modelnum" size="20" maxlength="20" onChange="formHandler(datasheet)">
<input type="button" name="GO" value="GO" onClick="formHandler(datasheet)">
</form>
<font face="Arial, Helvetica, sans-serif" size="2"><b>Enter model number and press "GO" to get data sheet</b></font>
</center>
</body>
</html>
<html>
<head>
<title>QuickSheet 1.0</title>
<script language="JavaScript">
function formHandler(datasheet){
var Spec = datasheet.modelnum.value.toUpperCase();
window.open("MYWEBSITEURL"+Spec+".pdf", "dataWindow", "status=yes,menubar=yes,location=yes,toolbar=no,scrollbars=yes"
;}
</script>
</head>
<body bgcolor="#666666" text="#FFFFFF" link="#EEEEEE" vlink="#CCCCCC" alink="#CC0033">
<center>
<form name="datasheet">
<input type="text" name="modelnum" size="20" maxlength="20" onChange="formHandler(datasheet)">
<input type="button" name="GO" value="GO" onClick="formHandler(datasheet)">
</form>
<font face="Arial, Helvetica, sans-serif" size="2"><b>Enter model number and press "GO" to get data sheet</b></font>
</center>
</body>
</html>