Kudis

function search_rus_symbol()
{
    var arTexts = document.getElementById('www1').innerHTML.match(/>([^\<]*)/ig);
    var arItems = [];
    arTexts.forEach(function(item, key){
        arItems[key] = item.replace(/([А-Яа-я]+)/mg, '<font color="red">$1</font>');
    });
    arTexts.forEach(function(item, key){
        document.getElementById('www1').innerHTML = document.getElementById('www1').innerHTML.replace(item, arItems[key]);
    });
}