Is my Javascirpt sentence is correct or not
How are you?

I need to know my javascript sentence is correct or not?
I am very much confused with the single quotes and pluse symbols.

document.f.SQL.value ='\('+ document.f.SQL.value + a[i] +' >= \''+ document.f[a[i]+"_A"].value  +'\' AND '+ a[i] +' <= \''+ document.f[a[i]+"_B"].value +'\) or DATEADD'+'\('+ 'dd, 0, DATEDIFF'+'\('+'dd, 0,'+ a[i] +'\))  = \''+ document.f[a[i]].value +'\'';

please help me.
Is my Javascirpt sentence is correct or not
===

How are you?

I need to know my javascript sentence is correct or not?
I am very much confused with the single quotes and pluse symbols.

document.f.SQL.value ='\('+ document.f.SQL.value + a[i] +' >= \''+ document.f[a[i]+"_A"].value  +'\' AND '+ a[i] +' <= \''+ document.f[a[i]+"_B"].value +'\) or DATEADD'+'\('+ 'dd, 0, DATEDIFF'+'\('+'dd, 0,'+ a[i] +'\))  = \''+ document.f[a[i]].value +'\'';

please help me.