function maxlength_textarea(id, crid, max)
{
var txtarea = document.getElementById(id);
document.getElementById(crid).innerHTML=max-txtarea.value.length;
txtarea.onkeypress=function(){eval('v_maxlength("'+id+'","'+crid+'",'+max+');')};
txtarea.onblur=function(){eval('v_maxlength("'+id+'","'+crid+'",'+max+');')};
txtarea.onkeyup=function(){eval('v_maxlength("'+id+'","'+crid+'",'+max+');')};
txtarea.onkeydown=function(){eval('v_maxlength("'+id+'","'+crid+'",'+max+');')};
}
function v_maxlength(id, crid, max)
{
var txtarea = document.getElementById(id);
var crreste = document.getElementById(crid);
var len = txtarea.value.length;
if(len>max)
{
txtarea.value=txtarea.value.substr(0,max);
}
len = txtarea.value.length;
crreste.innerHTML=max-len;
}