根据输入文本提示剩余数字个数
<script type="text/javascript"> function checkLength(which,lb) { var maxChars = 312; // if (which.value.length > maxChars) { // 超过限制的字数了就将 文本框中的内容按规定的字数 截取 which.value = which.value.substring(0,maxChars); return false; } else { var curr = maxChars - which.value.length; //250 减去 当前输入的 // alert(document.getElementById("sy")); if(lb==1) { document.getElementById("tabID_tabpID_ctlxswxInfo1_sy").innerHTML = curr.toString(); } else if(lb==2) { document.getElementById("tabID_tabpID_ctlxswxInfo1_sgfasy").innerHTML = curr.toString(); } return true; } } </script> <asp:TextBox ID="txtsgfa" runat="server" onkeyup="checkLength(this,2);" TextMode="MultiLine" MaxLength="312" Width="100%" Height="100%"></asp:TextBox>