input length

[verN]

how would i in javascript check that the user has entered characters less then for instance 20 if its more then a error is outputted.

 

<input type=text name=name> could i use onchnage to do this

 

thnaks

[paul2463]

yes write a simple javascript function that checks the input field length and outputs an error or does nothing at all

<input id="name" type="text" name="name" onChange="checkInput()">

function checkInput()
{
var str = document.getElementById("name").value;
if ( str.Length > 20 )
{
alert("Please enter less than 20 characters");
}
}

[rallokkcaz]

there is actually and even easier way to do it with out all the javascript

here is the code

<input id="name" type="text" name="name" maxlength="20">

its not complicated at all

and there can be no possibility that it will go over the limit

[paul2463]

Good idea rallokkcaz, that will work but wont throw the error requested

 

if its more then a error is outputted.

 

but both will work. one just prevents more than 20 the other one allows it but warns if you do, I suppose it comes down to information about the text box being available on the site to say that you are only allowed 20 characters etc.