Drop Down List Export Value

[sarmcgrah]

Not trying to do anything fancy, I just want the export value from a drop down list item to populate in a specific text box. I feel like it would be a fairly easy thing to do, but all the answers I've read so far are about Javascripts - is this necessary? How do you link the two fields? My drop down list is called "Support Item" and the text box is called "Support Item Number".

[sarmcgrah]

Update - I've just added the following script to the text box properties (Custom Format Script);

event.value = this.getField("Dropdown List").value;

It is now displaying the export value of the first drop down item however it will not change when other items are selected in the list. How can I fix this?

[sarmcgrah · Accepted solution]

Update - I was wrong to add it to Custom Format Script, I changed it to Calculate >  Custom Calculation Script and it is now working.