The if condition is executed, if both parameters have the same value.
IF_@ PARAM_EQUAL Variable1 Variable2
...
END_IF_@
Variable = defined variable of type - INTEGER | DOUBLE | STRING
@ = incremental number
Example:
SEARCH_MDL_PARAM THIS_12 DIAMETER DIA
SEARCH_MDL_PARAM THIS_10 DIAMETER DIA2
IF_1 PARAM_EQUAL DIA DIA2
...
END_IF_1