You can achieve this using simple css as shown in below example
button {_x000D_
overflow: visible;_x000D_
width: auto;_x000D_
}_x000D_
button.link {_x000D_
font-family: "Verdana" sans-serif;_x000D_
font-size: 1em;_x000D_
text-align: left;_x000D_
color: blue;_x000D_
background: none;_x000D_
margin: 0;_x000D_
padding: 0;_x000D_
border: none;_x000D_
cursor: pointer;_x000D_
_x000D_
-moz-user-select: text;_x000D_
_x000D_
/* override all your button styles here if there are any others */_x000D_
}_x000D_
button.link span {_x000D_
text-decoration: underline;_x000D_
}_x000D_
button.link:hover span,_x000D_
button.link:focus span {_x000D_
color: black;_x000D_
}
_x000D_
<button type="submit" class="link"><span>Button as Link</span></button>
_x000D_