Need some help with error handling..

[JavaMon]

Here is my assignment and I am a little confused. I barely know any JavaScript so this is kind of overwhelming.

Write JS code that anticipates and handles an error for an expected numeric field. This code is executed on keypress, and the entered value is saved for you in a variable called enteredChar. Include the try block of JS statements needed to check if the character is not a number or a non-alphanumeric character, or if you throw an error message.

Write a custom error handling JS function called processErrors that handles a custom error by assigning it to the onerror event handler. Include the block of JS statements needed to pass the arguments sent by the JS interpreter into the processErrors function, send an alert message with the agreements, return, and write the event handler that calls the processErrors function.

[JavaMon]

Here is what I got for the first part tell me what I can change to fix it please
<script type="text/javascript">
function validateNumber(formObject) {
try {
var number = formObject.value;
var numberCheck = ?
if (numberCheck.test(number) = false)
throw "One or more of the numbers
you entered
appear to be not valid.";
}
catch(numberError) {
window.alert(numberError)
return false;
}
return true;
}
</script>

[JavaMon]

K so here is what I got now for the first question would this work

<script type="text/javascript">
function validateNumber(formObject) {
var x=prompt("0","");
try
{
if(x>10)
{
throw "er1";
}
else if(x<0)
{
throw "er2";
}
else if(isNaN(x))
{
throw "er3";
}
}
catch(er)
{
if(er=="er1")
{
alert("Error: The value is too high");
}
if(er=="er2")
{
alert("Error: The value is too low");
}
if(er=="er3")
{
alert("Error: The value is invalid");
}
}
</script>

[JavaMon]

for the 2nd part it need to be like this
<script>
function handler(event) {
alert(event);
}
</script>


but I dont know what to do with that

[Padonak]

Here is what I got for the first part tell me what I can change to fix it please
<script type="text/javascript">
function validateNumber(formObject) {
try {
var number = formObject.value;
var numberCheck = ? // here goes a regular expression - something like /[\d]{1,}/g;
if (numberCheck.test(number) ==false)
throw "One or more of the numbers
you entered
appear to be not valid.";
}
catch(numberError) {
window.alert(numberError)
return false;
}
return true;
}
</script>

for the very first sight these 2 corrections must be done