diff --git a/JS/Tools.js b/JS/Tools.js
new file mode 100644
index 0000000..32f1030
--- /dev/null
+++ b/JS/Tools.js
@@ -0,0 +1,2 @@
+//textarea根据内容文字自动调整高度。注册textarea.oninput事件执行以下函数。
+function textareaAutoHeight(){this.style.height='auto'; this.style.height= this.scrollHeight;}
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