Script error on momentary button

this is my script on my momentary button

system.tag.write(event.source.parent.SOV_NO.Meta.TagPath+"/ManOpen",1)

it does high (i.e =1) my tag when i pressed my button but CANNOT put low (i.e =0) when i release button. as it is a momentary button it should be like " high on press and low on released" like positive pulse

Duplicate post. Try to not do that. See answer over in the first topic: