terraform.io example template for ec2 instance with tags

ec2.tf

# The various ${var.foo} come from variables.tf

# Specify the provider and access details
provider "aws" {
    region = "${var.aws_region}"
    access_key = "${var.aws_access_key}"
    secret_key = "${var.aws_secret_key}"
}


resource "aws_instance" "web" {
  # The connection block tells our provisioner how to
  # communicate with the resource (instance)
  connection {
    # The default username for our AMI
    user = "ubuntu"

    # The path to your keyfile
    key_file = "${var.key_path}"
  }

  # subnet ID for our VPC
  subnet_id = "${var.subnet_id}"
  # the instance type we want, comes from rundeck
  instance_type = "${var.instance_type}"

  # Lookup the correct AMI based on the region
  # we specified
  ami = "${lookup(var.aws_amis, var.aws_region)}"

  # The name of our SSH keypair you've created and downloaded
  # from the AWS console.
  #
  # https://console.aws.amazon.com/ec2/v2/home?region=us-west-2#KeyPairs:
  #
  key_name = "${var.key_name}"


  # We set the name as a tag
  tags {
    "Name" = "${var.instance_name"
  }
}

variables.tf

variable "key_name" {
    description = "Name of the SSH keypair to use in AWS."
}

variable "key_path" {
    description = "Path to the private portion of the SSH key specified."
}

variable "aws_region" {
    description = "AWS region to launch servers."
}

variable "aws_access_key" {
    decscription = "AWS Access Key"
}

variable "aws_secret_key" {
    description = "AWS Secret Key"
}

variable "subnet_id" {
    description = "Subnet ID to use in VPC"
}

variable "instance_type" {
    description = "Instance type"
}

variable "instance_name" {
    description = "Instance Name"
}

# Ubuntu Precise 12.04 LTS (x64)
variable "aws_amis" {
    default = {
        "eu-west-1": "ami-b1cf19c6",
        "us-east-1": "ami-de7ab6b6",
        "us-west-1": "ami-3f75767a",
        "us-west-2": "ami-21f78e11"
    }
}

how to give dynamic name to the aws-ec2 instance in this tf file.

There is a missing closing curly bracket in the ec2.tf on 41 line.

variable "aws_access_key" {
decscription = "AWS Access Key"
}

Typo mistake "description = AWS Access Key"

tags {
"Name" = "${var.instance_name}"
}