How to get comboBox selectedItem of one form into another form

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C#

C#4.0

hi,

How to get the selected item of combox in form to another form.(connect and Form1 )

in connect form :

<pre lang="c#"><pre lang="sql">public string machineId
        {
            get
            {
                return comboBox1.SelectedItem.ToString();
            }
            set
            {
                comboBox1.Text = value;
            }
        }</pre></pre>

and in Form1;

<pre lang="c#"><pre lang="c#">
                Connect c = new Connect();
                String machineid=c.machineId;

so i got the error as:at String machineid=c.machineId

Object reference not set to an instance of an object.