Count how many times specific words was appeared in text? [on hold]

Count how many times specific words was appeared in text? [on hold]

I have question for you guys. Lets say i'm writing an article, and i have
10 keywords, they should be mentioned in the text. If keyword is mentioned
i need to count how many times this word was in text. And all the amounts
should be showed at the top or bottom of textarea, for example in span, or
input, that doesnt matter. But how to ?
UPDATE:
sorry, i forgot to mention that i want to do it when i typing in textarea,
it needs to be made in jquery, onkeyup function.
function ck_jq()
{
var charsCount =
CKEDITOR.instances['article'].getData().replace(/<("[^"]*"|'[^']*'|[^'">])*>/gi,
'').replace(/^\s+|\s+$/g, '');
var wordCount = CKEDITOR.instances['article'].getData().replace(/[^\w
]/g, "").split(/\s+/);
var max = <?php echo $orderInfo->wordstarget; ?>;
//var max = 5;
if (wordCount >= max) {
var over = max - wordCount.length;
$("#wordstarget").css('color', 'red');
$("#characterscount").css('color', 'red');
$("#words").css('color', 'red');
$("#wordsleft").css('color', 'red');
// $("#wordscount").text(len.length + " characters and \n" +
wordCount + " words in this text. Words target: " + max +".
Words left: "+ char);
$("#wordstarget").text(max + " words target");
$("#characterscount").text(charsCount.length + " characters");
$("#words").text(wordCount.length + " words");
$("#wordsleft").text(over +" words left");
//$("#wordscount").css('color', 'red');
//$("#wordscount").text(len.length + " characters and \n" +
wordCount + " words in this text. Words target: " + max +".
Words left: "+ over);
} else {
var char = max - wordCount.length;
$("#wordstarget").css('color', 'green');
$("#characterscount").css('color', 'green');
$("#words").css('color', 'green');
$("#wordsleft").css('color', 'green');
// $("#wordscount").text(len.length + " characters and \n" +
wordCount + " words in this text. Words target: " + max +".
Words left: "+ char);
$("#wordstarget").text(max + " words target");
$("#characterscount").text(charsCount.length + " characters");
$("#words").text(wordCount.length + " words");
$("#wordsleft").text(char +" words left");
}
}
i'm using this to count just words and characters.