The 'ListBoxGetCurSel' function ruturns the index of the selected data of ListBox object.
int @ListBoxGetCurSel(string class_name);
Parameters
string class_name : class name of ListBox object
Return Value
index (If the number of data is four[10, 20, 30, 40], the index is as follows:10[index = 0], 20[index = 1], 30[index = 2], 40[index = 3])
Example
$AI_0000 = @ListBoxGetCurSel("ListBox1");
Description : Assume that data of 'ListBox1' are four[10, 20, 30, 40] and the selected data is '30'. If you excute the above statement, '2'(the index of data '30') is stored in the tag named 'AI_0000'.
Reference