JS實現規定TextBox長度，過濾關鍵字

<script language="javascript">  

  function   textCounter(field,   maxlimit)   {    

  if   (field.value.length   >   maxlimit)    

  field.value   =   field.value.substring(0,   maxlimit);    
  else if (field.value!=null)
    {
        var Sql_1 = " and | exec | count | chr | mid | master | or | truncate | char | declare | join |'|<|>|/*|*/|;|insert|select|delete|update|create|drop";
        var sql_c = Sql_1.split('|');
        for(var index=0;index<sql_c.length;++index)
        {
            if (field.value.indexOf(sql_c[index]) != -1) {
            field.value="";
      alert("包含非法關鍵字，請重新輸入。");    
         }
        }
    }  

  }  

</script>

 

再在相應TextBox加    onPropertyChange="textCounter(this,50)"