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Need Help with Number Validation

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Dec 29.2004

I am validating that a field called “number” is entered on my form with the following javascript code:

function FormValidator(theForm) {
if (theForm.number.value == “”) {
alert(“Please enter number.”);
theForm.number.focus();
return (false);
}
return (true);
}

Can anyone help me with the code required to extend this validation to ensure that only numbers (0-9) are entered i.e. no alpha or other characters and no blank spaces. Additionally (but not as important) how can I ensure that at least 6 but no more than 10 numbers are entered.

Many Thanks
PaulB

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JavaScript

3 Comments(s) ↴

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@NedalsDec 29.2004 — This uses a 'regular expression'
[size=1]
function FormValidator(theForm) {
if (!/d{6,10}/.test(theForm.number.value)) {
alert("Please enter number with 6 to 10 digits.");
theForm.number.focus();
return false;
}
return true;
}
[/size]
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@CharlesDec 29.2004 — If you take something that doesn't look like a number and try to cast it as a Number, NaN will be returned. And NaN evaluates to false in the boolean context. Thus:

[font=monospace]<input type="text" onchange="if (!Number (this.value)) {alert(); this.value=''}">[/font]
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@paulbauthorDec 29.2004 — Thanks so much - a real help !!!
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