function limitText(limitField, limitCount, limitNum) {
    if (limitField.value.length > limitNum) {
        limitField.value = limitField.value.substring(0, limitNum);
    } else {
        limitCount.value = limitNum - limitField.value.length;
    }
}

/* USAGE:
Step 2 - Create Text Area

text area:

<form name="myform">
<textarea name="limitedtextarea" onKeyDown="limitText(this.form.limitedtextarea,this.form.countdown,100);" 
onKeyUp="limitText(this.form.limitedtextarea,this.form.countdown,100);">
</textarea><br>
<font size="1">(Maximum characters: 100)<br>
You have <input readonly type="text" name="countdown" size="3" value="100"> characters left.</font>
</form>

single-line text field:

<form name="myform">
<input name="limitedtextfield" type="text" onKeyDown="limitText(this.form.limitedtextfield,this.form.countdown,15);" 
onKeyUp="limitText(this.form.limitedtextfield,this.form.countdown,15);" maxlength="15"><br>
<font size="1">(Maximum characters: 15)<br>
You have <input readonly type="text" name="countdown" size="3" value="15"> characters left.</font>
</form>
*/


function infopop(url) {
    window.open( url, "infoVindu", 
    "status = 1, height = 500, width = 500, resizable = 1, scrollbars=1" )
}