Custom Ribbon Button not Executing by Selenium Webdriver

Question

I am writing one automation script in this i am unable to click on a Custom RIbbon MSCRM2011 Button Below is HTML structure

<li id="contact|NoRelationship|Form|Mscrm.Form.contact.MainTab.ExportData" class="ms-cui-group" unselectable="on">
<span class="ms-cui-groupContainer" unselectable="on">
<span class="ms-cui-groupBody" unselectable="on">
<span id="contact|NoRelationship|Form|Mscrm.Form.contact.MainTab.ExportData-LargeMedium" class="ms-cui-layout" unselectable="on">
<span id="contact|NoRelationship|Form|Mscrm.Form.contact.MainTab.ExportData-LargeMedium-0" class="ms-cui-section" unselectable="on">
<span id="contact|NoRelationship|Form|Mscrm.Form.contact.MainTab.ExportData-LargeMedium-1" class="ms-cui-section" unselectable="on">
<span id="contact|NoRelationship|Form|Mscrm.Form.contact.MainTab.ExportData-LargeMedium-1-0" class="ms-cui-row" unselectable="on">
<a id="contact|NoRelationship|Form|fmc.contact.form.Button.Customer-Medium" class="ms-cui-ctl-medium " unselectable="on" href="javascript:;" onclick="return false;" aria-describedby="contact|NoRelationship|Form|fmc.contact.form.Button.Customer_ToolTip" mscui:controltype="Button" role="button">
<span class="ms-cui-ctl-iconContainer" unselectable="on">
<span class=" ms-cui-img-16by16 ms-cui-img-cont-float" unselectable="on">
<img unselectable="on" alt="" src="/%7B635732422790004376%7D/WebResources/fmc_/Images/HP.FMC.MSS360.CRM.Image.UpdateCustomer16X16">
</span>
</span>
<span class="ms-cui-ctl-mediumlabel" unselectable="on">Update Customer</span>
</a>
</span>

I got Below Exception

  org.openqa.selenium.WebDriverException: [JavaScript Error: "a is null" {file: "file:///C:/Users/kumarahi/AppData/Local/Temp/anonymous6568124592565267980webdriver-profile/extensions/[email protected]/components/command_processor.js" line: 8166}]'[JavaScript Error: "a is null" {file: "file:///C:/Users/kumarahi/AppData/Local/Temp/anonymous6568124592565267980webdriver-profile/extensions/[email protected]/components/command_processor.js" line: 8166}]' when calling method: [nsICommandProcessor::execute]
Command duration or timeout: 47 milliseconds
Build info: version: '2.41.0', revision: '3192d8a', time: '2014-03-27 17:18:15'
System info: host: 'KUMARAHI5', ip: '16.185.238.72', os.name: 'Windows 7', os.arch: 'amd64', os.version: '6.1', java.version: '1.7.0_79'
Session ID: 279f8847-4a64-4d6c-9ac9-9d703cc8faf4
Driver info: org.openqa.selenium.firefox.FirefoxDriver
Capabilities [{platform=XP, acceptSslCerts=true, javascriptEnabled=true, cssSelectorsEnabled=true, databaseEnabled=true, browserName=firefox, handlesAlerts=true, browserConnectionEnabled=true, webStorageEnabled=true, nativeEvents=false, rotatable=false, locationContextEnabled=true, applicationCacheEnabled=true, takesScreenshot=true, version=29.0}]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at org.openqa.selenium.remote.ErrorHandler.createThrowable(ErrorHandler.java:193)
    at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:145)
    at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:595)
    at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:348)
    at org.openqa.selenium.remote.RemoteWebDriver.findElementByXPath(RemoteWebDriver.java:445)
    at org.openqa.selenium.By$ByXPath.findElement(By.java:357)
    at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:340)
    at Ford_contact2.testWebdriverContact(Ford_contact2.java:117)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

for Button I have Written Some set of lines but none of the line is working

    driver.findElement(By.cssSelector("%7B635731557200004376%7D/WebResources/fmc_/Images/HP.FMC.MSS360.CRM.Image.UpdateCustomer16X16"));
 driver.findElement(By.cssSelector("img.ms-crm-ImageStrip-SaveAndClose_32")).click();
 driver.findElement(By.cssSelector("span. ms-cui-img-16by16 ms-cui-img-cont-float")).click();
 driver.findElement(By.cssSelector("a.ms-cui-ctl-medium ")).click();
     driver.findElement(By.xpath("//*[@id='contact|NoRelationship|Form|fmc.contact.form.Button.Customer-Medium']/span[1]/span/img']")).click();

Answer 1

Can you not just use this:

driver
    .findElement(By.id("contact|NoRelationship|Form|fmc.contact.form.Button.Customer-Medium"))
    .click();