plugin with id 'com.android.application' not found

I am new to android.I am using android studio 1.1.0.When i am building my project it says "Error:(1, 0) Plugin with id 'com.android.application' not found".What should i do?

Here is my "build.gradle" file-:\
// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
       jcenter()
     }
dependencies {
    classpath 'com.android.tools.build:gradle:1.1.0'

    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
  }}

  allprojects {
   repositories {
    jcenter()
    }}

and here is "build.gradle" file of module 'app'-:

  apply plugin: 'com.android.application'

  android {
     compileSdkVersion 22
     buildToolsVersion "22.0.1"

 defaultConfig {
     applicationId "healthcare.prescro.com.prescro"
     minSdkVersion 17
     targetSdkVersion 22
     versionCode 1
     versionName "1.0"
   }
 buildTypes {
     release {
         minifyEnabled false
         proguardFiles getDefaultProguardFile('proguard-android.txt'),   'proguard-rules.pro'
       }
  }}

  dependencies {
      compile fileTree(dir: 'libs', include: ['*.jar'])
      compile 'com.android.support:appcompat-v7:22.0.0'
      compile 'com.google.android.gms:play-services:7.0.0'
      compile project(path: ':backend_gcm', configuration: 'android-endpoints')}                                                                                        

Here is the log-:

2015-10-02 00:07:36,306 [ 73561] WARN - nal.AbstractExternalSystemTask - Plugin with id 'com.android.application' not found. com.intellij.openapi.externalSystem.model.LocationAwareExternalSystemException: Plugin with id 'com.android.application' not found. at org.jetbrains.plugins.gradle.service.project.AbstractProjectImportErrorHandler.createUserFriendlyError(AbstractProjectImportErrorHandler.java:103) at org.jetbrains.plugins.gradle.service.project.BaseProjectImportErrorHandler.getUserFriendlyError(BaseProjectImportErrorHandler.java:153) at org.jetbrains.plugins.gradle.service.project.BaseGradleProjectResolverExtension.getUserFriendlyError(BaseGradleProjectResolverExtension.java:358) at org.jetbrains.plugins.gradle.service.project.AbstractProjectResolverExtension.getUserFriendlyError(AbstractProjectResolverExtension.java:151) at com.android.tools.idea.gradle.project.AndroidGradleProjectResolver.getUserFriendlyError(AndroidGradleProjectResolver.java:322) at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver$ProjectConnectionDataNodeFunction.fun(GradleProjectResolver.java:367) at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver$ProjectConnectionDataNodeFunction.fun(GradleProjectResolver.java:333) at org.jetbrains.plugins.gradle.service.project.GradleExecutionHelper.execute(GradleExecutionHelper.java:203) at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver.resolveProjectInfo(GradleProjectResolver.java:116) at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver.resolveProjectInfo(GradleProjectResolver.java:64) at com.intellij.openapi.externalSystem.service.remote.RemoteExternalSystemProjectResolverImpl$1.produce(RemoteExternalSystemProjectResolverImpl.java:41) at com.intellij.openapi.externalSystem.service.remote.RemoteExternalSystemProjectResolverImpl$1.produce(RemoteExternalSystemProjectResolverImpl.java:37) at com.intellij.openapi.externalSystem.service.remote.AbstractRemoteExternalSystemService.execute(AbstractRemoteExternalSystemService.java:59) at com.intellij.openapi.externalSystem.service.remote.RemoteExternalSystemProjectResolverImpl.resolveProjectInfo(RemoteExternalSystemProjectResolverImpl.java:37) at com.intellij.openapi.externalSystem.service.remote.wrapper.ExternalSystemProjectResolverWrapper.resolveProjectInfo(ExternalSystemProjectResolverWrapper.java:49) at com.intellij.openapi.externalSystem.service.internal.ExternalSystemResolveProjectTask.doExecute(ExternalSystemResolveProjectTask.java:48) at com.intellij.openapi.externalSystem.service.internal.AbstractExternalSystemTask.execute(AbstractExternalSystemTask.java:137) at com.intellij.openapi.externalSystem.service.internal.AbstractExternalSystemTask.execute(AbstractExternalSystemTask.java:123) at com.intellij.openapi.externalSystem.util.ExternalSystemUtil$2.execute(ExternalSystemUtil.java:406) at com.intellij.openapi.externalSystem.util.ExternalSystemUtil$3$2.run(ExternalSystemUtil.java:483) at com.intellij.openapi.progress.impl.ProgressManagerImpl$TaskRunnable.run(ProgressManagerImpl.java:471) at com.intellij.openapi.progress.impl.ProgressManagerImpl$2.run(ProgressManagerImpl.java:178) at com.intellij.openapi.progress.ProgressManager.executeProcessUnderProgress(ProgressManager.java:209) at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:212) at com.intellij.openapi.progress.impl.ProgressManagerImpl.runProcess(ProgressManagerImpl.java:171) at com.intellij.openapi.progress.impl.ProgressManagerImpl$8.run(ProgressManagerImpl.java:380) at com.intellij.openapi.application.impl.ApplicationImpl$8.run(ApplicationImpl.java:419) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) at java.util.concurrent.FutureTask.run(FutureTask.java:262) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745) at com.intellij.openapi.application.impl.ApplicationImpl$1$1.run(ApplicationImpl.java:149)