js中response值的问题

js文件里面
alert(response)；
打印出：
{"fileName":null,"localFilePath":"E:\\Tomcat 6.0\\webapps\\file\\message\\12999504454325060.jpg","path":"E:\\Tomcat 6.0\\webapps\\file\\message","uploadFile":{"absolute":true,"absoluteFile":null,"absolutePath":"E:\\temp\\upload__22947e27_12eaade4568__8000_00000094.tmp","canonicalFile":null,"canonicalPath":"E:\\temp\\upload__22947e27_12eaade4568__8000_00000094.tmp","directory":false,"file":true,"freeSpace":30718992384,"hidden":false,"name":"upload__22947e27_12eaade4568__8000_00000094.tmp","parent":"E:\\temp","parentFile":{"absolute":true,"absoluteFile":null,"absolutePath":"E:\\temp","canonicalFile":null,"canonicalPath":"E:\\temp","directory":true,"file":false,"freeSpace":30718992384,"hidden":false,"name":"temp","parent":"E:\\","parentFile":{"absolute":true,"absoluteFile":null,"absolutePath":"E:\\","canonicalFile":null,"canonicalPath":"E:\\","directory":true,"file":false,"freeSpace":30718992384,"hidden":true,"name":"","parent":null,"parentFile":null,"path":"E:\\","totalSpace":83889594368,"usableSpace":30718992384},"path":"E:\\temp","totalSpace":83889594368,"usableSpace":30718992384},"path":"E:\\temp\\upload__22947e27_12eaade4568__8000_00000094.tmp","totalSpace":83889594368,"usableSpace":30718992384},"uploadFileFileName":"ava.jpg"}如果我只想要“localFilePath” 的值“E:\\Tomcat 6.0\\webapps\\file\\message\\12999504454325060.jpg”我该怎么做，小弟在此，求各位大侠解答