How to check if a field exists using iMacro

I Need to check to see if an html field exists in a website using iMacro plugin for fi开发者_JAVA技巧refox. If the field does not exist, then I need to perform a different opperation

TAG POS=1 TYPE=A ATTR=TXT:C

TAG POS= Which A class do yo want.

Type= To find your text in that class

ATTR= What do want from that class. (TXT, HREF...)

TXT(or something different): You can use * to find anything in class. İt marks the object. Or you want to search example:

TAG POS=1 TYPE=B ATTR=TXT:I<sp>am<sp>a<sp>text.

This code means find the first bold item which is in text:I am a text, and mark it.