How to use operator "OR" in a conditional statement

Hi,

I am using following conditional statements to display 4 different images based on 4 different values (1, 2, 3, or 4) in TREATMENT_ID column. The following conditional statement is working, however i want to edit it to use "OR" since the image is the same for the values 1 and 2:

<% if (targetData.TREATMENT_ID == '1'){%>

<img class="setImageFull" src="http://img/image1.png" width="600" height="82" alt="Rewards Certificate"/>

<% } else if (targetData.TREATMENT_ID == '2'){%>

<img class="setImageFull" src="http://img/image1.png" width="600" height="82" alt="Rewards Certificate"/>

<% } else if (targetData.TREATMENT_ID == '3'){%>

<img class="setImageFull" src="http://img/image3.png" width="600" height="82" alt="Rewards Certificate"/>

<% } else if (targetData.TREATMENT_ID == '4'){%>

<img class="setImageFull" src="http://img/image4.png" width="600" height="82" alt="Rewards Certificate"/>

<%}%>

Here is the edited code. Does this would work:

<% if (targetData.TREATMENT_ID == '1') Or (targetData.TREATMENT_ID == '2')  {%>

<img class="setImageFull" src="http://img/image1.png" width="600" height="82" alt="Rewards Certificate"/>

Thanks!

AK