The border-top-style CSS property sets the style of the top border of a box.
object.style.borderTopStyle = "value";
<'border-top-style'> = <line-style>
<line-style> = none | hidden | dotted | dashed | solid | double | groove | ridge | inset | outset
A dashed line. A series of square-ended dashes.
A dotted line. A series of round dots.
A double line. Two parallel solid lines with some space between them.
A grooved line. Looks as if it were carved in the canvas.
A hidden line. Same as none, but has different behavior in the border conflict resolution rules for border-collapsed tables.
An inset line. Looks as if the content on the inside of the border is sunken into the canvas.
An outset line. Looks as if the content on the inside of the border is coming out of the canvas.
A ridged line. Looks as if it were coming out of the canvas.
A single line.