left expression is of type BIGINT and right expression is of type STRING and the operator == is not valid

left expression is of type BIGINT and right expression is of type STRING and the operator == is not valid

Hi, sorry for my English it's not soo good.

I have one problem, I have one form with a single line field call "Title"and a subform(Task) in the same form, in the subform I have a Look up field call "Name", I try to put the data of the single fiel "Title" in the Look up field "Name",  and I get this error:

In Criteria left expression is of type BIGINT and right expression is of type STRING and the operator == is not valid

This is my code:

temp = Project[ID==input.Title];
row.Name = temp;


Please help me with this, thanks.