Issue with accentuation in asp.net

Hello Everyone,

I am working with one multilanguage website. I am facing one issue into that while writing accentuation into the textbox.
When i write down some thing like Fábrica das Verdadeiras Queijadas da Sapa and then Press tab then it converts the text to Fbrica das Verdadeiras Queijadas da Sapa.
So can any one provide me the solution, how can i put same values in textbox. I am using below syntax for the input textbox

<input type="text" placeholder="Write here..." onclick="this.placeholder = ''" onblur="this.placeholder='Write here...'" id="txtSearchName" />

Please help me asap, because now, its an urgent kind of issue for me.

Thanks