Replace value in XPath with Variable

Below is the sample piece of code for submitting the variable into XPath.
Selenium IDE
<tr>
    <td>store</td>
    <td>2</td>
    <td>a</td>
</tr>

Verify the A value
<tr>
    <td>echo</td>
    <td>${a}</td>
    <td></td>
</tr>

//Replace the hardcoded value with a
<tr>
    <td>click</td>
    <td>//*[@id='ctl00_Main_DropDown']/div/ul/li[${a}]</td>
    <td></td>
</tr>

In Selenium RC
String a = "2";
System.out.println(a);
selenium.click("//*[@id='ctl00_Main_DropDown']/div/ul/li[" + a + "]");

dragAndDropToObject

Selenium IDE doesn't support Drag and Drop by recording but it can support if we add manually. Below is the sample piece code for dragAndDropToObject.

Selenium IDE
<tr>
    <td>dragAndDropToObject</td>
    <td>//*[@id='ctl00_chMain_Period']/span</td>
//Locator value of element to be dragged
    <td>//*[@id='ctl00_chMain_Period']/ul/li[5]/span</td>
//Locator value of destination object
</tr>
Selenium RC
selenium.dragAndDropToObject("//*[@id='ctl00_chMain_Period']/span", "//*[@id='ctl00_chMain_Period']/ul/li[5]/span"); 

StoreAttribute

It is very important in automation to store the specific attribute to verify in next iteration.

Below script will explain how to use the  StoreAttribute command

<tr>
    <td>storeAttribute</td>
    <td>//*[@id='lst-ib']@name</td>
    <td>Attribute</td>
</tr>
<tr>
    <td>echo</td>
    <td>${Attribute}</td>
    <td></td>
</tr>

Let me know if you have further doubts.