Javascript example code to implement real string remaining character prompt_javascript skills

//The number of remaining words in the text box (character size)
function textLimitCheckSj(thisArea, maxLength, SpanId) {
var str = thisArea.value;
if (getChrLen(str, maxLength) > maxLength * 2) {
thisArea.value = str.substring (0, x-1);
}
else {
var varss = '(Number of words remaining:' Math.floor((maxLength * 2 - getChrLen(str, maxLength)) / 2) ') ';
document.getElementById(SpanId).innerHTML = varss;
}
}
function getChrLen(str, maxLength) {
var realLength = 0, len = str.length, charCode = -1;
x = 0;
for (; (x < len) && (realLength <=maxLength * 2); x ) {
charCode = str.charCodeAt(x); < ​​​​Return realLength;
} <🎜 < ;/asp:TextBox>                                                                                                                                                                                         style="color: #808080"> (within 50 words)