_javascript technique of JS code for computing the remaining Chang degree of text field

JS calculates the remaining words in the text field <textarea cols= "rows=" 4 "onkeyup=" Displaysparenumber (this,10) "onchange=" Displaysparenumber (this "></textarea> <script type=" Text/javascript "language=" JavaScript "> Function Displaysparenumber ( _this,size) {var Sparenumber=document.getelementbyid ("Sparenumber"); Chinese character length var len=_this.value.replace (/[^\x00-\xff]/gi, ' xx '). var snum=parseint (size)-len; Sparenumber.value=snum; if (snum<0) {if (_this.value.length!=len) {if (len-_this.value.length) > (SIZE/2)) {_this.value=_this.value.sub String (0,SIZE/2); else {_this.value=_this.value.substring (0,size-(len-_this.value.length)); } else {_this.value=_this.value.substring (0,size); } sparenumber.value=0; Return } </script> left <input id= "Sparenumber" name= "Sparenumber" value= "1" size= <br><br> Note: <br> Displaysparenumber (this,10) <br> and <br> <input id= "Sparenumber" name= "Sparenumber" value= "10 "size=" 1 "/The 10 in > <br> is the length of the content you define.
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