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limiting number of lines of TextArea

speed2
speed2 asked
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Last Modified: 2008-03-03
Can we limit the number os lines user can type in textarea
using javascript? Thx.
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Commented:
I guess you're trying to prevent a message from being too long? You could always count newlines or just prevent the length of the entire string from being longer than some size.

I think something like the following would do both; I haven't checked this so consider it a serving suggestion:

var s = form.text.value;
if ( s.length > 100 ) alert("don't type so much");

var lines = 1;
var i = -1;
while ( ( i = s.indexOf("\n",i+1) >= 0 )  lines++;
if ( lines > 10 ) alert("too many lines");

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Commented:
Thanks for answers from both of you. I guess my question is
how can I let the user know when they are still typing. "onChange" will only be activated if the user onFocus from the
textArea field. Thx a lot.

Author

Commented:
It isn't possible any other way using javascript.....
Perhaps if you need this level of protection in your textarea you should investigate putting your form in a java applet.
This would enable you to do a lot more rigorous checking on the textarea.
Your right though on most browsers the onChange method of the textarea isn't really called on every change.  This is kind of misleading for this event handler.

Good luck
Pete
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