How to create a Function to connect to SQL

I would like to turn this into a function and am having trouble

$ServerInstance = "MYSERVER "
$Database = "MY_DB "
$ConnectionTimeout = 30
$Query = "SELECT Models FROM CARS"
$QueryTimeout = 120
$List = 'D:\PScript\List.csv'

$conn=new-object System.Data.SqlClient.SQLConnection
$ConnectionString = "Server={0};Database={1};Integrated Security=True;Connect Timeout={2}" -f $ServerInstance,$Database,$ConnectionTimeout
$conn.ConnectionString=$ConnectionString
$conn.Open()
$cmd=new-object system.Data.SqlClient.SqlCommand($Query,$conn)
$cmd.CommandTimeout=$QueryTimeout
$ds=New-Object system.Data.DataSet
$da=New-Object system.Data.SqlClient.SqlDataAdapter($cmd)
[void]$da.fill($ds)
$conn.Close()
$ds.Tables

#$ds.Tables[0] | ConvertTo-CSV | select -Skip 2 > $List