Suppress Eval all column formula

[#1]

I was trying to use the script below to suppress eval or allow eval for all column formula in the table. For some reason, I kept getting an error (see snapshot) on the third time running the script but I can't particularly find the bug. Appreciate the community help in debugging this. 

names default to here(1);

dt = current data table();

try(formula_suppress = dt:Formula_Suppress,
	dt << set table variable("Formula_Suppress",1);
	formula_suppress = 1;
);
wait(0.5);

formula_suppress = abs(formula_suppress - 1);
dt << set table variable("Formula_Suppress",formula_suppress);
//show(formula_suppres);

for(i=1,i<=ncol(dt),i++,
	as column(dt,i) << suppress eval(formula_suppress)
);

if(formula_suppress == 1,
	status = "Suppressed",
	status = "Evaluated"
);

NewWindow("Alert",
	showToolbars(0),showMenu(0),BorderBox(top(15),bottom(15),left(15),right(15),
		VListBox(
			TextBox("Formulas in the table are " || char(status),<<setFontStyle("bold"),<<fontcolor("red")),
			SpacerBox(size(0,15)),
		HCenterBox(ButtonBox("         close         ",current window()<<close window ))
		)
	)
);

[#2 · Accepted solution]

The syntax error that was causing the failure was because the 

formula_suppress = dt:Formula_Suppress,

was not returning what you were expecting.  Below is a rework of the code that returns properly when the Table Variable does not exist

names default to here(1);

dt = current data table();

if(try(isempty(dt:Formula_Suppress),1) == 1,
	dt << set table variable("Formula_Suppress",1);
	formula_suppress = 1;
);
wait(0.5);

formula_suppress = abs(formula_suppress - 1);
dt << set table variable("Formula_Suppress",formula_suppress);
//show(formula_suppres);

for(i=1,i<=ncol(dt),i++,
	as column(dt,i) << suppress eval(formula_suppress)
);

if(formula_suppress == 1,
	status = "Suppressed",
	status = "Evaluated"
);

NewWindow("Alert",
	showToolbars(0),showMenu(0),BorderBox(top(15),bottom(15),left(15),right(15),
		VListBox(
			TextBox("Formulas in the table are " || char(status),<<setFontStyle("bold"),<<fontcolor("red")),
			SpacerBox(size(0,15)),
		HCenterBox(ButtonBox("         close         ",current window()<<close window ))
		)
	)
);