Regular Expression For Arabic Language

Try this:-

function HasArabicCharacters(text)
{
    var arregex = /[\u0600-\u06FF]/;
    alert(arregex.test(text));
} 

Arabic character set of list

[\u0600-\u06ff]|[\u0750-\u077f]|[\ufb50-\ufc3f]|[\ufe70-\ufefc]

Arabic script in Unicode:

As of Unicode 6.1, the Arabic script is contained in the following blocks:

Arabic (0600—06FF, 225 characters)
Arabic Supplement (0750—077F, 48 characters)
Arabic Extended-A (08A0—08FF, 39 characters)
Arabic Presentation Forms-A (FB50—FDFF, 608 characters)
Arabic Presentation Forms-B (FE70—FEFF, 140 characters)
Rumi Numeral Symbols (10E60—10E7F, 31 characters)
Arabic Mathematical Alphabetic Symbols (1EE00—1EEFF, 143 characters)

Contents are taken from wikipedia - Arabic script in Unicode

I'd suggest this :

\p{InArabic}